613 results on '"Stevens MM"'
Search Results
52. Collagen-mimetic peptide-modifiable hydrogels for articular cartilage regeneration
- Author
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Parmar, PA, Chow, LW, St-Pierre, J-P, Horejs, C-M, Peng, YY, Werkmeister, JA, Ramshaw, JAM, Stevens, MM, Parmar, PA, Chow, LW, St-Pierre, J-P, Horejs, C-M, Peng, YY, Werkmeister, JA, Ramshaw, JAM, and Stevens, MM
- Abstract
Regenerative medicine strategies for restoring articular cartilage face significant challenges to recreate the complex and dynamic biochemical and biomechanical functions of native tissues. As an approach to recapitulate the complexity of the extracellular matrix, collagen-mimetic proteins offer a modular template to incorporate bioactive and biodegradable moieties into a single construct. We modified a Streptococcal collagen-like 2 protein with hyaluronic acid (HA) or chondroitin sulfate (CS)-binding peptides and then cross-linked with a matrix metalloproteinase 7 (MMP7)-sensitive peptide to form biodegradable hydrogels. Human mesenchymal stem cells (hMSCs) encapsulated in these hydrogels exhibited improved viability and significantly enhanced chondrogenic differentiation compared to controls that were not functionalized with glycosaminoglycan-binding peptides. Hydrogels functionalized with CS-binding peptides also led to significantly higher MMP7 gene expression and activity while the HA-binding peptides significantly increased chondrogenic differentiation of the hMSCs. Our results highlight the potential of this novel biomaterial to modulate cell-mediated processes and create functional tissue engineered constructs for regenerative medicine applications.
- Published
- 2015
53. Research with vulnerable families caring for children with life-limiting conditions.
- Author
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Stevens, MM, Lord, BA, Proctor, M-T, Nagy, S, O'Riordan, E, Stevens, MM, Lord, BA, Proctor, M-T, Nagy, S, and O'Riordan, E
- Abstract
Methodological challenges associated with sensitive research, such as research with vulnerable families, have been well described, but there are few examples of how such challenges have been addressed in specific projects. To help address this gap, we describe how we designed and conducted a qualitative study of 91 members of 29 families caring for children or young people with life-limiting conditions. Although some issues associated with researching sensitive topics were anticipated, others were encountered that were not expected. We discuss insights gained from this study in relation to factors that influence effectiveness of recruitment, the quality of data collection, and the safety of participants and researchers.
- Published
- 2010
54. Emergence phenology of Chironomus tepperi Skuse and Procladius paludicola Skuse (Diptera: Chironomidae) during rice crop establishment in southern New South Wales
- Author
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Stevens, MM, primary
- Published
- 1994
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55. Field evaluation of plaster-based temephos pellets for residual control of midge larvae (Diptera: Chironomidae) in establishing rice crops
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Stevens, MM, primary and Warren, GN, additional
- Published
- 1994
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56. Taxonomy, cladistics and biogeography of the Australian genus Putoniessa Kirkaldy (Hemiptera : Cicadelloidea : Cicadellidae)
- Author
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Stevens, MM, primary
- Published
- 1994
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57. Revision of the genus Alseis Kirkaldy (Homoptera : Cicadelloidea : Cicadellidae), with descriptions of six new species
- Author
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Stevens, MM, primary
- Published
- 1991
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58. A revision of the genus Epipsychidion Kirkaldy (Homoptera : Cicadelloidea : Cicadellidae)
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Stevens, MM, primary
- Published
- 1990
- Full Text
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59. E-mail communication between medical students and schoolchildren: a model for medical education.
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Bernhardt AM, Dalton MA, Sargent JD, and Stevens MM
- Published
- 2000
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60. Mammography in New Hampshire: characteristics of the women and the exams they receive.
- Author
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Carney PA, Goodrich ME, O'Mahony DM, Tosteson AN, Eliassen MS, Poplack SP, Birnbaum S, Harwood BG, Burgess KA, Berube BT, Wells WS, Ball JP, and Stevens MM
- Abstract
New Hampshire (NH) is one of two states that has developed a population-based mammography registry. The purpose of this paper is to describe what we have learned about mammography use in New Hampshire. After collecting data for 20 months, the database contains almost 110,000 mammographic encounters representing 101,679 NH women, who range in age from 18 to 97 with a mean of 56.7 years (SD=10.91). Education levels are high with 92% having a high school education and 59% with some college. Forty-six percent report their primary insurance is private, 29% report HMO/PPO coverage, and 25% receive federal health care assistance. Risk factors represented in the database include (categories not mutually exclusive) advancing age (60% over age 50), hormone replacement therapy use by menopausal women (40.6%), and a family history of breast cancer (29%). Penetration of mammography relative to the NH population is higher for younger age groups (40-48% for those aged 44-64) than older age groups (34-39% for those aged 65-84). The majority of mammographic encounters are routine screening exams (86%), often interpreted as negative or normal with benign findings (88%). Use of comparison films to interpret either diagnostic or screening mammography occurred in 86% of encounters. We have matched 3,877 breast pathology records to these mammographic encounters. The distribution of pathology outcomes for diagnostic exams was very similar to that for screening exams (approximately 65% benign, 17% invasive breast cancer, and 6% noninvasive breast cancer). Overall, we have designed a system that is well accepted by the NH community. Challenges include careful monitoring of data for coding errors, and a limitation of linking variables in mammography and pathology data. Data represented in this registry are a critical resource for research in mammographic screening and breast cancer early detection. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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61. Risk of basal cell and squamous cell skin cancers after ionizing radiation therapy. For The Skin Cancer Prevention Study Group.
- Author
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Karagas MR, McDonald JA, Greenberg ER, Stukel TA, Weiss JE, Baron JA, Stevens MM, Karagas, M R, McDonald, J A, Greenberg, E R, Stukel, T A, Weiss, J E, Baron, J A, and Stevens, M M
- Abstract
Background: Human evidence that ionizing radiation is carcinogenic first came from reports of nonmelanoma skin cancers (NMSCs) on the hands of workers using early radiation devices. An increased risk of NMSC has been observed among uranium miners, radiologists, and individuals treated with x rays in childhood for tinea capitis (ringworm of the scalp) or for thymic enlargement; NMSC is one of the cancers most strongly associated with the atomic bombing of Hiroshima and Nagasaki. Although exposure to ionizing radiation is a known cause of NMSC, it is not yet clear whether therapeutic radiation causes both major histologic types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Additionally, the potentially modifying effects, such as latency, age when treated, and type of treatment, are not well understood.Purpose: We investigated the relative risks of BCC and SCC associated with previous radiation therapy and evaluated these risks in relation to age and time since initial treatment and the medical condition for which radiation therapy was given.Methods: The study group comprised individual diagnosed with at least one BCC or SCC from January 1980 through February 1986, who were recruited to participate in a skin cancer prevention trial designed to test whether oral beta-carotene supplementation would reduce the risk of new NMSCs. Patients were identified through the dermatology and pathology records of academic medical centers in Hanover, NH; Los Angeles, CA; San Francisco, CA; and Minneapolis, MN. Each participant completed a questionnaire detailing lifetime residence, pigmentary characteristics, occupational and recreational sun exposure, and history of radiation therapy. At enrollment, a study dermatologist assessed skin type (tendency to burn or tan) and extent of actinic skin damage. Participants were followed with an annual dermatologic examination for an average of 4 years. Of the 5232 potentially eligible individuals, 1805 were enrolled in the trial. We excluded 112 patients who reported previous radiation therapy for skin cancer only and three with missing information on whether they were ever treated with radiation therapy, leaving 1690 patients for the analysis. Approximately 4% of the patients died or discontinued participation for other reasons during each study year. We examined time to occurrence of first new histopathologically confirmed BCC and SCC during the follow-up period in relation to history of radiation therapy (for reasons other than NMSC) using a proportional hazards model. A multiple end points survival model was used to compare the rate ratios (RRs) for BCC and SCC. We also used a longitudinal method of analysis to compute the RR of total new BCC and SCC tumors per person per study year associated with radiation therapy. Using this method, we additionally assessed the potential modifying effects of age at treatment, latency, and type of therapy. All P values were derived from two-sided statistical tests of significance.Results: Among the participants we studied, 597 developed a new BCC (n = 1553 tumors) and 118 developed a new SCC (n = 179 tumors). The time to first new BCC, but not SCC, was associated with prior radiation therapy (RR = 1.7; 95% confidence interval [CI] = 1.4-2.0 and RR = 1.0; 95% CI = 0.6-1.7, respectively; P = .03 for the difference between the RRs). The RR of total BCC tumors was slightly higher (RR = 2.3; 95% CI = 1.7-3.1), but it was still unity for SCC (RR = 1.0; 95% CI = 0.5-1.9). BCC risk appeared to increase with younger age at exposure and time since initially treated, although these effects were only marginally statistically significant (P for trend = .06 and .07, respectively). Also, risk of BCC was more strongly related to treatment for acne (RR = 3.3; 95% CI = 2.1-5.2) than other conditions.Conclusions and Implications: Our data suggest that exposure to therapeutic radiation is associated with BCC but not with SCC. [ABSTRACT FROM AUTHOR]- Published
- 1996
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62. Something new under the sun.
- Author
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Stevens MM
- Abstract
Two hygienists use Extended Care Permits to extend access to oral preventive care for underserved Kansans in nursing homes and public schools. [ABSTRACT FROM AUTHOR]
- Published
- 2006
63. Sequence-Dependent Self-Assembly and Structural Diversity of Islet Amyloid Polypeptide-Derived β-Sheet Fibrils
- Author
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Wang, ST, Lin, Y, Spencer, RK, Thomas, MR, Nguyen, AI, Amdursky, N, Pashuck, ET, Skaalure, SC, Song, C, Parmar, PA, Morgan, RM, Ercius, P, Aloni, S, Zuckermann, RN, Stevens, MM, Engineering & Physical Science Research Council (E, Engineering & Physical Science Research Council (EPSRC), and Commission of the European Communities
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Amyloid ,Hydrogen Bonding ,self-assembly ,helical nanostructures ,Microscopy, Atomic Force ,Article ,Islet Amyloid Polypeptide ,amyloid fibrils ,X-Ray Diffraction ,MD Multidisciplinary ,Humans ,Protein Conformation, beta-Strand ,Amino Acid Sequence ,Nanoscience & Nanotechnology ,Hydrophobic and Hydrophilic Interactions ,nanoribbons - Abstract
© 2017 American Chemical Society. Determining the structural origins of amyloid fibrillation is essential for understanding both the pathology of amyloidosis and the rational design of inhibitors to prevent or reverse amyloid formation. In this work, the decisive roles of peptide structures on amyloid self-assembly and morphological diversity were investigated by the design of eight amyloidogenic peptides derived from islet amyloid polypeptide. Among the segments, two distinct morphologies were highlighted in the form of twisted and planar (untwisted) ribbons with varied diameters, thicknesses, and lengths. In particular, transformation of amyloid fibrils from twisted ribbons into untwisted structures was triggered by substitution of the C-terminal serine with threonine, where the side chain methyl group was responsible for the distinct morphological change. This effect was confirmed following serine substitution with alanine and valine and was ascribed to the restriction of intersheet torsional strain through the increased hydrophobic interactions and hydrogen bonding. We also studied the variation of fibril morphology (i.e., association and helicity) and peptide aggregation propensity by increasing the hydrophobicity of the peptide side group, capping the N-terminus, and extending sequence length. We anticipate that our insights into sequence-dependent fibrillation and morphological diversity will shed light on the structural interpretation of amyloidogenesis and development of structure-specific imaging agents and aggregation inhibitors.
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64. Online quantitative monitoring of live cell engineered cartilage growth using diffuse fiber-optic Raman spectroscopy
- Author
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Bergholt, M, Albro, M, Stevens, MM, Medical Research Council (MRC), and Commission of the European Communities
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Fiber-optic Raman spectroscopy ,Live cell Raman spectroscopy ,MD Multidisciplinary ,Biomedical Engineering ,Tissue-engineering ,Online biomedical Raman spectroscopy ,Articular cartilage - Abstract
Tissue engineering (TE) has the potential to improve the outcome for patients with osteoarthritis (OA). The successful clinical translation of this technique as part of a therapy requires the ability to measure extracellular matrix (ECM) production of engineered tissues in vitro, in order to ensure quality control and improve the likelihood of tissue survival upon implantation. Conventional techniques for assessing the ECM content of engineered cartilage, such as biochemical assays and histological staining are inherently destructive. Raman spectroscopy, on the other hand, represents a non-invasive technique for in situ biochemical characterization. Here, we outline current roadblocks in translational Raman spectroscopy in TE and introduce a comprehensive workflow designed to non-destructively monitor and quantify ECM biomolecules in large (>3 mm), live cell TE constructs online. Diffuse near-infrared fiber-optic Raman spectra were measured from live cell cartilaginous TE constructs over a 56-day culturing period. We developed a multivariate curve resolution model that enabled quantitative biochemical analysis of the TE constructs. Raman spectroscopy was able to non-invasively quantify the ECM components and showed an excellent correlation with biochemical assays for measurement of collagen (R2 = 0.84) and glycosaminoglycans (GAGs) (R2 = 0.86). We further demonstrated the robustness of this technique for online prospective analysis of live cell TE constructs. The fiber-optic Raman spectroscopy strategy developed in this work offers the ability to non-destructively monitor construct growth online and can be adapted to a broad range of TE applications in regenerative medicine toward controlled clinical translation.
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65. Taxonomy, cladistics and biogeography of the Australian genus Putoniessa Kirkaldy (Hemiptera : Cicadelloidea : Cicadellidae)
- Author
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Stevens, MM
- Abstract
The morphology of Putoniessa Kirkaldy is reviewed and the genus revised. In total, 28 species are recognised: the type species, P. dignissima Kirkaldy, which is removed from synonymy; one new combination, P. dorsalis (Walker); eight previously described species, P. nigra (Walker), P. minima Evans, P. mackei Evans, P. draba Evans, P. taradalensis Evans, P. sordida Evans, P. nigrella Evans and P. turneri Evans; and 18 new species, P. rieki, P, brisbanensis, P. hickmani, P, neboissi, P. stanthorpensis, P. woodwardi, P. striata, P. evansi, P. variegata, P. tasmaniensis, P. grossi, P. serrata, P. northamensis, P. bifurcata, P. kiataensis, P. watsoni, P. fusca and P. aroka. P. nota Evans is excluded from the genus, and P. maculata Evans is synonymised under P. dorsalis (Walker). P. rivularis (Walker), originally described under Bythoscopus Germar, and P. galliensis Evans are considered as species of uncertain identity. The genus is shown to have a disjunct Bassian distribution with some eastern species extending northwards into the south-east of the Tomesian province. A consensus cladogram for Putoniessa, based on morphological characters, is presented. Large areas of the cladogram remain unresolved because of high levels of homoplasy among the limited number of reliable ingroup characters available. The cladogram does not support a purely vicariant biogeographic hypothesis. Theories that receive qualified support involve an eastern origin for the group followed by either an east-to-west dispersal or a vicariance event affecting a single taxon subsequent to initial speciation. A western origin for the group is strongly refuted.
- Published
- 1994
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66. Microcosm assessment of potential molluscicides for control of the rice snail Isidorella newcombi sens. lat. (Gastropoda: Basommatophora: Planorbidae)
- Author
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Stevens, MM, Faulder, RJ, and Coombes, NE
- Abstract
Twenty-seven pesticides were evaluated for their toxicity to mature Isidorella newcombi (Adams & Angas), a serious pest of irrigated rice in NSW, Australia. Evaluations were conducted using microcosms in which typical field conditions were simulated. Only 3 compounds, niclosamide, n-tritylmorpholine, and nicotinanilide, provided >95% mortality at an initial screening rate of 3 mg/L. These compounds were assessed at a range of rates using both immediate and delayed-exposure bioassays to determine LC values and comparative persistence. Niclosamide (as Bayer Bayluscide 250 g/L EC) and n-tritylmorpholine (as Shell FresconB 165 g/L EC) were the most toxic (LC90, immediate exposure, 0.19 mg/L for both compounds), whilst the corresponding LC90 value for nicotinanilide (laboratory grade in DMSO) was 0.53 mg/L. Persistence (reflected by a slower increase in LC90 values over time in delayed exposure bioassays) was strongest in nicotinanilide and weakest in n-tritylmorpholine. Although niclosamide is the most promising compound for the control of I. newcombi, further development of nicotinanilide is also recommended, as it represents a potentially valuable tool for use in situations where low fish toxicity is required.
- Published
- 1996
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67. A revision of the genus Epipsychidion Kirkaldy (Homoptera : Cicadelloidea : Cicadellidae)
- Author
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Stevens, MM
- Abstract
The Australian cicadellid genus Epipsychidion Kirkaldy is revised. Two species are recognised: E. epipyropis Kirkaldy (the type species) and E. whitteni Evans. E. fides Evans is synonymised with E. epipyropis, and a lectotype designated for the latter. A key is provided to the males of the genus, and the known distributions of both species are mapped.
- Published
- 1990
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68. Revision of the genus Alseis Kirkaldy (Homoptera : Cicadelloidea : Cicadellidae), with descriptions of six new species
- Author
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Stevens, MM
- Abstract
The genus Alseis Kirkaldy is revised. Seven species are recognised: the type species, A. osborni Kirkaldy, and six new species, A. noccundraensis, A. brittoni, A. gattonensis, A. awoongaensis, A. hackeri and A. monstrosa. The genus is known only from eastern Australia. The known distributions of all species are mapped, and a key to males of the genus is presented.
- Published
- 1991
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69. Stage IV-S neuroblastoma: disseminated malignancy with a favourable prognosis. Three case reports
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Stevens Mm
- Subjects
Oncology ,Male ,medicine.medical_specialty ,Pathology ,business.industry ,Liver Neoplasms ,Infant ,Disease ,medicine.disease ,Malignancy ,Prognosis ,Neuroblastoma ,Internal medicine ,Pediatrics, Perinatology and Child Health ,medicine ,Etiology ,Humans ,Female ,Retroperitoneal Neoplasms ,Neoplasm Metastasis ,business ,Stage iv ,Neoplasm Staging - Abstract
Stevens, M.M. (1979).Aust. Paediatr. J., 15, 39–43. Stage IV-S neuroblastoma: disseminated malignancy with a favourable prognosis. Three cases reports. The case histories of three children with stage IV-S neuroblastoma are presented to illustrate the clinical features and unusual behaviour of this form of neuroblastoma. The staging requirements for this specific pattern of disease are presented and possible mechanisms of aetiology and regression and recommended management are discussed.
- Published
- 1979
70. The tooth fairy's friend.
- Author
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Stevens MM
- Abstract
School teachers can emphasize dental education through a variety of classroom activites, and the author finds an enthusiastic 'friend' in a Kansas elementary school. [ABSTRACT FROM AUTHOR]
- Published
- 2004
71. School-based care.
- Author
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Stevens MM
- Abstract
Modern-day tooth fairies are alive and well in Kansas, thanks to the efforts of a hygienist determined 'to do something about it.' [ABSTRACT FROM AUTHOR]
- Published
- 2004
72. On the dynamic behaviour of the forced dissociation of ligand-receptor pairs
- Author
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Williams, Pm, Moore, A., Stevens, Mm, Allen, S., Davies, Mc, Clive Roberts, and Tendler, Sjb
73. Raman Spectroscopy Reveals New Insights into the Zonal Organization of Native and Tissue-Engineered Articular Cartilage
- Author
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Bergholt, MS, St-Pierre, J-P, Offeddu, GS, Parmar, PA, Albro, MB, Puetzer, JL, Oyen, ML, and Stevens, MM
- Subjects
0903 Biomedical Engineering ,Biomedical ,Basic Science ,5.2 Cellular and gene therapies ,Arthritis ,Musculoskeletal ,Bioengineering ,0601 Biochemistry and Cell Biology ,Regenerative Medicine ,3. Good health - Abstract
Tissue architecture is intimately linked with its functions, and loss of tissue organization is often associated with pathologies. The intricate depth-dependent extracellular matrix (ECM) arrangement in articular cartilage is critical to its biomechanical functions. In this study, we developed a Raman spectroscopic imaging approach to gain new insight into the depth-dependent arrangement of native and tissue-engineered articular cartilage using bovine tissues and cells. Our results revealed previously unreported tissue complexity into at least six zones above the tidemark based on a principal component analysis and k-means clustering analysis of the distribution and orientation of the main ECM components. Correlation of nanoindentation and Raman spectroscopic data suggested that the biomechanics across the tissue depth are influenced by ECM microstructure rather than composition. Further, Raman spectroscopy together with multivariate analysis revealed changes in the collagen, glycosaminoglycan, and water distributions in tissue-engineered constructs over time. These changes were assessed using simple metrics that promise to instruct efforts toward the regeneration of a broad range of tissues with native zonal complexity and functional performance.
74. Raman spectroscopic imaging for quantification of depth-dependent and local heterogeneities in native and engineered cartilage
- Author
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Albro, M, Bergholt, M, St-Pierre, JP, Vinals Guitart, A, Zlotnick, HM, Evita, EG, Stevens, MM, Wellcome Trust, Medical Research Council (MRC), and Commission of the European Communities
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lcsh:R ,lcsh:Medicine - Abstract
Articular cartilage possesses a remarkable, mechanically-robust extracellular matrix (ECM) that is organized and distributed throughout the tissue to resist physiologic strains and provide low friction during articulation. The ability to characterize the make-up and distribution of the cartilage ECM is critical to both understand the process by which articular cartilage undergoes disease-related degeneration and to develop novel tissue repair strategies to restore tissue functionality. However, the ability to quantitatively measure the spatial distribution of cartilage ECM constituents throughout the tissue has remained a major challenge. In this experimental investigation, we assessed the analytical ability of Raman micro-spectroscopic imaging to semi-quantitatively measure the distribution of the major ECM constituents in cartilage tissues. Raman spectroscopic images were acquired of two distinct cartilage tissue types that possess large spatial ECM gradients throughout their depth: native articular cartilage explants and large engineered cartilage tissue constructs. Spectral acquisitions were processed via multivariate curve resolution to decompose the “fingerprint” range spectra (800–1800 cm−1) to the component spectra of GAG, collagen, and water, giving rise to the depth dependent concentration profile of each constituent throughout the tissues. These Raman spectroscopic acquired-profiles exhibited strong agreement with profiles independently acquired via direct biochemical assaying of spatial tissue sections. Further, we harness this spectroscopic technique to evaluate local heterogeneities through the depth of cartilage. This work represents a powerful analytical validation of the accuracy of Raman spectroscopic imaging measurements of the spatial distribution of biochemical components in a biological tissue and shows that it can be used as a valuable tool for quantitatively measuring the distribution and organization of ECM constituents in native and engineered cartilage tissue specimens.
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75. Use of silver sulphadiazine cream for burns caused by cytotoxic‐drug extravasation
- Author
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Stevens Mm, Peter J. Shaw, Nightingale We, and Bergin Me
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medicine.medical_specialty ,Cytotoxic drug ,business.industry ,Sulfadiazine ,Antineoplastic Agents ,General Medicine ,Silver Sulfadiazine ,Dermatology ,Silver sulphadiazine ,Extravasation ,Burns, Chemical ,Humans ,Medicine ,Child ,business ,Extravasation of Diagnostic and Therapeutic Materials - Published
- 1988
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76. Rural adolescent drinking behavior: Three year follow-up in the New Hampshire substance abuse...
- Author
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Stevens MM and Mott LA
- Abstract
A three-year follow-up study of alcohol prevention among 4,406 children showed that neither a comprehensive school curriculum nor a community intervention was successful in preventing adolescent drinking. Predictor variables for drinking are examined and the importance of tolerance and encouragement of drinking by adult role models are noted. [ABSTRACT FROM AUTHOR]
- Published
- 1996
77. Assessing for concussion.
- Author
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Stevens MM
- Published
- 1991
78. The measurement of symptoms in young children with cancer: the validation of the Memorial Symptom Assessment Scale in children aged 7-12.
- Author
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Collins JJ, Devine TD, Dick GS, Johnson EA, Kilham HA, Pinkerton CR, Stevens MM, Thaler HT, Portenoy RK, Collins, John J, Devine, Tom D, Dick, Gina S, Johnson, Elizabeth A, Kilham, Henry A, Pinkerton, C Ross, Stevens, M M, Thaler, Howard T, and Portenoy, Russell K
- Abstract
Few studies have attempted to describe the experience of symptoms in young children with cancer. This is due, in part, to the lack of validated symptom assessment scales for this patient population. The objective of this study was to evaluate the reliability and validity of a revised Memorial Symptom Assessment Scale (MSAS) in patients aged 7-12 as an instrument for the assessment of symptoms in young children with cancer. The MSAS (7-12) was administered to 149 children (inpatients and outpatients) who were undergoing treatment at either the Royal Marsden NHS Trust, London, United Kingdom or The Children's Hospital at Westmead, Sydney, Australia. Validity was evaluated by comparison with the medical record, parental report, and concurrent assessment on visual analogue scales for selected symptoms. The data provide evidence of the reliability and validity of MSAS (7-12) and demonstrate that children with cancer as young as 7 years can report clinically relevant and consistent information about their symptom experience. Young children with cancer experience multiple symptoms. Approximately one-third had experienced lethargy and/or pain and/or insomnia during the 48 hours prior to the completion of MSAS (7-12). The completion rate for MSAS (7-12) was high and the majority of children completed the instrument in a short period of time and with little difficulty. The instrument appears to be age appropriate and may be helpful to older children unable to independently complete MSAS (10-18). Systematic symptom assessment may be useful in future epidemiological studies of symptoms and in cancer chemotherapy drug trials. [ABSTRACT FROM AUTHOR]
- Published
- 2002
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79. Improving electrospun fibre stacking with direct writing for developing scaffolds for tissue engineering for non-load bearing bone
- Author
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Sam Liao, Keith A. Blackwood, Jiongyu Edward Ren, Nathalie Bock, Mia Woodruff, Nikola Ristovski, Giles T. S. Kirby, Roland Steck, Molly M. Stevens, Blackwood, KA, Ristovski, N, Liao, S, Bock, N, Ren, J, Kirby, GTS, Stevens, MM, Steck, R, Woodruff, MA, and 5th International Conference on the Development of Biomedical Engineering in Vietnam Ho Chi Minh City, Vietnam 16-18 June 2015
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Materials science ,business.industry ,Stacking ,3D printing ,bioactive glass ,Electrospinning ,law.invention ,Tissue engineering ,law ,polycaprolactone ,Bioactive glass ,Deposition (phase transition) ,Composite material ,business ,Nanoscopic scale ,Melt electrospinning ,Engineering, Biomedical ,electrospinning - Abstract
Melt electrospinning can be used to produce fibres within the micro to nano scale with a deposition in a manner in-line with conventional 3D printing technology's [1]. Technical issues such as charge build up in subsequent layers lead to limitations in the precision of fibre deposition as the number of layers increases. Polycaprolactone (PCL) is a polyester with a wellestablished history as a scaffold material for bone tissue engineering [2]. It is biocompatible, easy to shape and mechanically suitable for bone defects. Bioactive glasses are ceramic materials which are known to stimulate osteogenic differentiation [3]. The combination of PCL and bioactive glasses present the possibility to develop osteogenic scaffolds with a high degree of control of laydown using melt electrospinning [4]. This work develops the potential of melt electrospinning as a scaffold fabrication technique for tissue engineering non-load bearing bone defects by both developing techniques for improcing fibre laydown introducing osteogenic factors. Refereed/Peer-reviewed
- Published
- 2015
80. Investigating The Role of Elastin and Extracellular Matrix Damage in Cardiovascular Calcification.
- Author
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Radvar E, Mehta K, D'Ambrosio A, Mastroianni G, Al-Jawad M, Stevens MM, Mata A, and Elsharkawy S
- Abstract
Although calcification in the cardiovascular system is highly studied, the mechanisms behind it are not well understood. Current proposed mechanisms focus on cellular processes leading to, or controlling the unwanted mineralization in soft tissues. However, extracellular components such as collagen and elastin fundamentally regulate the mechanical properties of heart tissues. Here, we report on a toolkit to control the composition of tissues through the selective digestion of extracellular matrix (ECM) components, which can be used to design disease-specific in vitro models. Using this technique, we show that elastin as well as matrix tissue damage may play major role in cardiovascular calcification. This study highlights a novel approach to understand the role of proteins in soft tissue calcifications and may lead to the development of strategies to treat and prevent these unwanted pathological disorders., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
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81. Unlocking Intracellular Protein Delivery by Harnessing Polymersomes Synthesized at Microliter Volumes using Photo-PISA.
- Author
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Thanapongpibul C, Rifaie-Graham O, Ojansivu M, Najer A, Kim H, Bakker SE, Chami M, Peeler DJ, Liu C, Yeow J, and Stevens MM
- Subjects
- Humans, Proteins chemistry, Polymerization, Animals, Drug Carriers chemistry, Endosomes metabolism, Mice, Polymers chemistry
- Abstract
Efficient delivery of therapeutic proteins and vaccine antigens to intracellular targets is challenging due to generally poor cell membrane permeation and endolysosomal entrapment causing degradation. Herein, these challenges are addressed by developing an oxygen-tolerant photoinitiated polymerization-induced self-assembly (Photo-PISA) process, allowing for the microliter-scale (10 µL) synthesis of protein-loaded polymersomes directly in 1536-well plates. High-resolution techniques capable of analysis at a single particle level are employed to analyze protein encapsulation and release mechanisms. Using confocal microscopy and super-resolution stochastic optical reconstruction microscopy (STORM) imaging, their ability to deliver proteins into the cytosol following endosomal escape is subsequently visualized. Lastly, the adaptability of these polymersomes is exploited to encapsulate and deliver a prototype vaccine antigen, demonstrating its ability to activate antigen-presenting cells and support antigen cross-presentation for applications in subunit vaccines and cancer immunotherapy. This combination of ultralow volume synthesis and efficient intracellular delivery holds significant promise for unlocking the high throughput screening of a broad range of otherwise cost-prohibitive or early-stage therapeutic protein and vaccine antigen candidates that can be difficult to obtain in large quantities. The versatility of this platform for rapid screening of intracellular protein delivery can result in significant advancements across the fields of nanomedicine and biomedical engineering., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)
- Published
- 2024
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82. Non-invasive in vivo sensing of bacterial implant infection using catalytically-optimised gold nanocluster-loaded liposomes for urinary readout.
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Chen K, Najer A, Charchar P, Saunders C, Thanapongpibul C, Klöckner A, Chami M, Peeler DJ, Silva I, Panariello L, Karu K, Loynachan CN, Frenette LC, Potter M, Tregoning JS, Parkin IP, Edwards AM, Clarke TB, Yarovsky I, and Stevens MM
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- Animals, Mice, Female, Colorimetry methods, Humans, Catalysis, Molecular Dynamics Simulation, Hyaluronic Acid chemistry, Prostheses and Implants microbiology, Hydrogels chemistry, Gold chemistry, Metal Nanoparticles chemistry, Biosensing Techniques methods, Staphylococcus aureus isolation & purification, Liposomes chemistry, Staphylococcal Infections diagnosis, Staphylococcal Infections microbiology
- Abstract
Staphylococcus aureus is a leading cause of nosocomial implant-associated infections, causing significant morbidity and mortality, underscoring the need for rapid, non-invasive, and cost-effective diagnostics. Here, we optimise the synthesis of renal-clearable gold nanoclusters (AuNCs) for enhanced catalytic activity with the aim of developing a sensitive colourimetric diagnostic for bacterial infection. All-atom molecular dynamics (MD) simulations confirm the stability of glutathione-coated AuNCs and surface access for peroxidase-like activity in complex physiological environments. We subsequently develop a biosensor by encapsulating these optimised AuNCs in bacterial toxin-responsive liposomes, which is extensively studied by various single-particle techniques. Upon exposure to S. aureus toxins, the liposomes rupture, releasing AuNCs that generate a colourimetric signal after kidney-mimetic filtration. The biosensor is further validated in vitro and in vivo using a hyaluronic acid (HA) hydrogel implant infection model. Urine samples collected from mice with bacteria-infected HA hydrogel implants turn blue upon substrate addition, confirming the suitability of the sensor for non-invasive detection of implant-associated infections. This platform has significant potential as a versatile, cost-effective diagnostic tool., Competing Interests: Competing interests: The authors declare the following competing financial interest(s): M.M.S. has filed a patent application (1810010.7) and has a registered trademark (US Reg. No. 6088213) covering the name SPARTA® and the techniques, described in the manuscript by Penders et al. https://doi.org/10.1038/s41467-018-06397-6 . M.M.S. is a founder of Sparta Biodiscovery Ltd. C.N.L. and M.M.S. have filed a patent application (US20200116725 A1) on renal clearable nanocatalysts for disease monitoring. The remaining authors declare no competing interests., (© 2024. The Author(s).)
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- 2024
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83. Hyperspectral unmixing for Raman spectroscopy via physics-constrained autoencoders.
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Georgiev D, Fernández-Galiana Á, Vilms Pedersen S, Papadopoulos G, Xie R, Stevens MM, and Barahona M
- Abstract
Raman spectroscopy is widely used across scientific domains to characterize the chemical composition of samples in a nondestructive, label-free manner. Many applications entail the unmixing of signals from mixtures of molecular species to identify the individual components present and their proportions, yet conventional methods for chemometrics often struggle with complex mixture scenarios encountered in practice. Here, we develop hyperspectral unmixing algorithms based on autoencoder neural networks, and we systematically validate them using both synthetic and experimental benchmark datasets created in-house. Our results demonstrate that unmixing autoencoders provide improved accuracy, robustness, and efficiency compared to standard unmixing methods. We also showcase the applicability of autoencoders to complex biological settings by showing improved biochemical characterization of volumetric Raman imaging data from a monocytic cell., Competing Interests: Competing interests statement:M.M.S. holds part-time appointments at Imperial College London and the Karolinska Institute. M.M.S. is founder of Sparta Biodiscovery Ltd. which commercializes a technology for single particle Raman spectroscopy. M.M.S. is inventor in a patent describing a technique for SPARTA, a technique for single particle Raman spectroscopy (1810010.7), and in a patent describing Raman tags (2314282.1/GB/PRV). M.M.S. invested in, consults for (or was on scientific advisory boards or boards of directors), and conducts sponsored research funded by companies related to the biomaterials field.
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- 2024
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84. Tunable Hybrid Hydrogels of Alginate and Cell-Derived dECM to Study the Impact of Matrix Alterations on Epithelial-to-Mesenchymal Transition.
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Barros da Silva P, Zhao X, Bidarra SJ, Nascimento DS, LaLone V, Lourenço BN, Paredes J, Stevens MM, and Barrias CC
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- Humans, Epithelial Cells metabolism, Epithelial Cells drug effects, Epithelial Cells cytology, Fibroblasts metabolism, Fibroblasts cytology, Fibroblasts drug effects, Breast Neoplasms metabolism, Breast Neoplasms pathology, Female, Epithelial-Mesenchymal Transition drug effects, Alginates chemistry, Alginates pharmacology, Hydrogels chemistry, Hydrogels pharmacology, Extracellular Matrix metabolism, Transforming Growth Factor beta1 metabolism, Transforming Growth Factor beta1 pharmacology
- Abstract
Epithelial-to-mesenchymal transition (EMT) is crucial for tumor progression, being linked to alterations in the extracellular matrix (ECM). Understanding the ECM's role in EMT can uncover new therapeutic targets, yet replicating these interactions in vitro remains challenging. It is shown that hybrid hydrogels of alginate (ALG) and cell-derived decellularized ECM (dECM), with independently tunable composition and stiffness, are useful 3D-models to explore the impact of the breast tumor matrix on EMT. Soft RGD-ALG hydrogels (200 Pa), used as neutral bulk material, supported mammary epithelial cells morphogenesis without spontaneous EMT, allowing to define the gene, protein, and biochemical profiles of cells at different TGFβ1-induced EMT states. To mimic the breast tumor composition, dECM from TGFβ1-activated fibroblasts (adECM) are generated, which shows upregulation of tumor-associated proteins compared to ndECM from normal fibroblasts. Using hybrid adECM-ALG hydrogels, it is shown that the presence of adECM induces partial EMT in normal epithelial cells, and amplifes TGF-β1 effects compared to ALG and ndECM-ALG. Increasing the hydrogel stiffness to tumor-like levels (2.5 kPa) have a synergistic effect, promoting a more evident EMT. These findings shed light on the complex interplay between matrix composition and stiffness in EMT, underscoring the utility of dECM-ALG hydrogels as a valuable in vitro platform for cancer research., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)
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- 2024
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85. Bioactive coatings on 3D printed scaffolds for bone regeneration: Use of Laponite® to deliver BMP-2 in an ovine femoral condyle defect model.
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Marshall KM, McLaren JS, Wojciechowski JP, Callens SJP, Echalier C, Kanczler JM, Rose FRAJ, Stevens MM, Dawson JI, and Oreffo ROC
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- Animals, Sheep, Coated Materials, Biocompatible chemistry, Osteogenesis drug effects, Disease Models, Animal, Bone Morphogenetic Protein 2 administration & dosage, Bone Morphogenetic Protein 2 pharmacology, Bone Regeneration drug effects, Silicates chemistry, Silicates pharmacology, Silicates administration & dosage, Tissue Scaffolds chemistry, Printing, Three-Dimensional, Femur pathology, Femur injuries, Femur drug effects
- Abstract
Biomaterial-based approaches for bone regeneration seek to explore alternative strategies to repair non-healing fractures and critical-sized bone defects. Fracture non-union occurs due to a number of factors resulting in the formation of bone defects. Rigorous evaluation of the biomaterials in relevant models and assessment of their potential to translate towards clinical use is vital. Large animal experimentation can be used to model fracture non-union while scaling-up materials for clinical use. Growth factors modulate cell phenotype, behaviour and initiate signalling pathways leading to changes in matrix deposition and tissue formation. Bone morphogenetic protein-2 (BMP-2) is a potent osteogenic growth factor, with a rapid clearance time in vivo necessitating clinical use at a high dose, with potential deleterious side-effects. The current studies have examined the potential for Laponite® nanoclay coated poly(caprolactone) trimethacrylate (PCL-TMA900) scaffolds to bind BMP-2 for enhanced osteoinduction in a large animal critical-sized bone defect. An ovine femoral condyle defect model confirmed PCL-TMA900 scaffolds coated with Laponite®/BMP-2 produced significant bone formation compared to the uncoated PCL-TMA 900 scaffold in vivo, assessed by micro-computed tomography (μCT) and histology. This indicated the ability of Laponite® to deliver the bioactive BMP-2 on the PCL-TMA900 scaffold. Bone formed around the Laponite®/BMP-2 coated PCL-TMA900 scaffold, with no erroneous bone formation observed away from the scaffold material confirming localisation of BMP-2 delivery. The current studies demonstrate the ability of a nanoclay to localise and deliver bioactive BMP-2 within a tailored octet-truss scaffold for efficacious bone defect repair in a large animal model with significant implications for translation to the clinic., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Prof Richard Oreffo reports financial support was provided by Biotechnology and Biological Sciences Research Council. Prof Molly Stevens reports financial support was provided by UK Regenerative Medicine Platform, and she invested in, consults for (or is on the scientific advisory boards or boards of directors) and conducts sponsored research funded by companies related to the biomaterials field. R.O.C. Oreffo and J.I. Dawson are co-founders and shareholders in a university spin out company with a license to IP indirectly related to the current manuscript. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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86. Considerations of growth factor and material use in bone tissue engineering using biodegradable scaffolds in vitro and in vivo.
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Marshall KM, Wojciechowski JP, Jayawarna V, Hasan A, Echalier C, Øvrebø Ø, Yang T, Zhou K, Kanczler JM, Mata A, Salmeron-Sanchez M, Stevens MM, and Oreffo ROC
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- Animals, Mice, Bone and Bones metabolism, Bone and Bones drug effects, Polyesters chemistry, Alkaline Phosphatase metabolism, Humans, Biocompatible Materials chemistry, Biocompatible Materials pharmacology, Coated Materials, Biocompatible chemistry, Coated Materials, Biocompatible pharmacology, Tissue Scaffolds chemistry, Tissue Engineering methods, Bone Morphogenetic Protein 2 metabolism, Osteogenesis drug effects
- Abstract
Bone tissue engineering aims to harness materials to develop functional bone tissue to heal 'critical-sized' bone defects. This study examined a robust, coated poly(caprolactone) trimethacrylate (PCL-TMA) 3D-printable scaffold designed to augment bone formation. Following optimisation of the coatings, three bioactive coatings were examined, i) elastin-like polypeptide (ELP), ii) poly(ethyl acrylate) (PEA), fibronectin (FN) and bone morphogenetic protein-2 (BMP-2) applied sequentially (PEA/FN/BMP-2) and iii) both ELP and PEA/FN/BMP-2 coatings applied concurrently. The scaffold material was robust and showed biodegradability. The coatings demonstrated a significant (p < 0.05) osteogenic response in vitro in alkaline phosphatase gene upregulation and alkaline phosphatase production. The PCL-TMA scaffold and coatings supported angiogenesis and displayed excellent biocompatibility following evaluation on the chorioallantoic membrane assay. No significant (p < 0.05) heterotopic bone formed on the scaffolds within a murine subcutaneous implantation model, compared to the positive control of BMP-2 loaded collagen sponge following examination by micro-computed tomography or histology. The current studies demonstrate a range of innovative coated scaffold constructs with in vitro efficacy and clearly illustrate the importance of an appropriate in vivo environment to validate in vitro functionality prior to scale up and preclinical application., (© 2024. The Author(s).)
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- 2024
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87. Transfer Learning Bayesian Optimization to Design Competitor DNA Molecules for Use in Diagnostic Assays.
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Sedgwick R, Goertz JP, Stevens MM, Misener R, and van der Wilk M
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With the rise in engineered biomolecular devices, there is an increased need for tailor-made biological sequences. Often, many similar biological sequences need to be made for a specific application meaning numerous, sometimes prohibitively expensive, lab experiments are necessary for their optimization. This paper presents a transfer learning design of experiments workflow to make this development feasible. By combining a transfer learning surrogate model with Bayesian optimization, we show how the total number of experiments can be reduced by sharing information between optimization tasks. We demonstrate the reduction in the number of experiments using data from the development of DNA competitors for use in an amplification-based diagnostic assay. We use cross-validation to compare the predictive accuracy of different transfer learning models, and then compare the performance of the models for both single objective and penalized optimization tasks.
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- 2024
88. Transfer learning Bayesian optimization for competitor DNA molecule design for use in diagnostic assays.
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Sedgwick R, Goertz JP, Stevens MM, Misener R, and van der Wilk M
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With the rise in engineered biomolecular devices, there is an increased need for tailor-made biological sequences. Often, many similar biological sequences need to be made for a specific application meaning numerous, sometimes prohibitively expensive, lab experiments are necessary for their optimization. This paper presents a transfer learning design of experiments workflow to make this development feasible. By combining a transfer learning surrogate model with Bayesian optimization, we show how the total number of experiments can be reduced by sharing information between optimization tasks. We demonstrate the reduction in the number of experiments using data from the development of DNA competitors for use in an amplification-based diagnostic assay. We use cross-validation to compare the predictive accuracy of different transfer learning models, and then compare the performance of the models for both single objective and penalized optimization tasks., (© 2024 The Author(s). Biotechnology and Bioengineering published by Wiley Periodicals LLC.)
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- 2024
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89. Physical-property-based patterning: simply engineering complex tissues.
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Zlotnick HM, Stevens MM, and Mauck RL
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- Humans, Animals, Tissue Engineering methods
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The field of biofabrication is rapidly expanding with the advent of new technologies and material systems to engineer complex tissues. In this opinion article, we introduce an emerging tissue patterning method, physical-property-based patterning, that has strong translational potential given its simplicity and limited dependence on external hardware. Physical-property-based patterning relies solely on the intrinsic density, magnetic susceptibility, or compressibility of an object, its surrounding solution, and the noncontact application of a remote field. We discuss how physical properties can be exploited to pattern objects and design a variety of biologic tissues. Finally, we pose several open questions that, if addressed, could transform the status quo of biofabrication, pushing us one step closer to patterning tissues in situ., Competing Interests: Declaration of interests MMS invested in, consults for (or was on the scientific advisory boards or boards of directors) and conducts sponsored research funded by companies related to the biomaterials field. RLM cofounded, is on the scientific advisory board, and conducts sponsored research funded by companies related to the biomaterials field. HMZ consults for a company related to the biomaterials field. HMZ and RLM have submitted a patent application that relates to magnetic susceptibility-based patterning (US Patent App. 17/229,829)., (Published by Elsevier Ltd.)
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- 2024
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90. Fundamentals and Applications of Raman-Based Techniques for the Design and Development of Active Biomedical Materials.
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Fernández-Galiana Á, Bibikova O, Vilms Pedersen S, and Stevens MM
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- Humans, Nanoparticles chemistry, Tissue Engineering, Animals, Spectrum Analysis, Raman methods, Biocompatible Materials chemistry
- Abstract
Raman spectroscopy is an analytical method based on light-matter interactions that can interrogate the vibrational modes of matter and provide representative molecular fingerprints. Mediated by its label-free, non-invasive nature, and high molecular specificity, Raman-based techniques have become ubiquitous tools for in situ characterization of materials. This review comprehensively describes the theoretical and practical background of Raman spectroscopy and its advanced variants. The numerous facets of material characterization that Raman scattering can reveal, including biomolecular identification, solid-to-solid phase transitions, and spatial mapping of biomolecular species in bioactive materials, are highlighted. The review illustrates the potential of these techniques in the context of active biomedical material design and development by highlighting representative studies from the literature. These studies cover the use of Raman spectroscopy for the characterization of both natural and synthetic biomaterials, including engineered tissue constructs, biopolymer systems, ceramics, and nanoparticle formulations, among others. To increase the accessibility and adoption of these techniques, the present review also provides the reader with practical recommendations on the integration of Raman techniques into the experimental laboratory toolbox. Finally, perspectives on how recent developments in plasmon- and coherently-enhanced Raman spectroscopy can propel Raman from underutilized to critical for biomaterial development are provided., (© 2023 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)
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- 2024
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91. Strong sequence-dependence in RNA/DNA hybrid strand displacement kinetics.
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Smith FG, Goertz JP, Jurinović K, Stevens MM, and Ouldridge TE
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- Kinetics, Thermodynamics, Base Sequence, RNA chemistry, DNA chemistry, Nucleic Acid Hybridization
- Abstract
Strand displacement reactions underlie dynamic nucleic acid nanotechnology. The kinetic and thermodynamic features of DNA-based displacement reactions are well understood and well predicted by current computational models. By contrast, understanding of RNA/DNA hybrid strand displacement kinetics is limited, restricting the design of increasingly complex RNA/DNA hybrid reaction networks with more tightly regulated dynamics. Given the importance of RNA as a diagnostic biomarker, and its critical role in intracellular processes, this shortfall is particularly limiting for the development of strand displacement-based therapeutics and diagnostics. Herein, we characterise 22 RNA/DNA hybrid strand displacement systems, alongside 11 DNA/DNA systems, varying a range of common design parameters including toehold length and branch migration domain length. We observe that differences in stability between RNA-DNA hybrids and DNA-DNA duplexes have large effects on strand displacement rates, with rates for equivalent sequences differing by up to 3 orders of magnitude. Crucially, however, this effect is strongly sequence-dependent, with RNA invaders strongly favoured in a system with RNA strands of high purine content, and disfavoured in a system when the RNA strands have low purine content. These results lay the groundwork for more general design principles, allowing for creation of de novo reaction networks with novel complexity while maintaining predictable reaction kinetics.
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- 2024
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92. A Facile Method to Quantify Synthetic Peptide Concentrations on Biomaterials.
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Wojciechowski JP, Benge T, Chen K, Echalier C, Xie R, and Stevens MM
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- Humans, Nanoparticles chemistry, Osteogenesis drug effects, Peptides chemistry, Peptides pharmacology, Mesenchymal Stem Cells drug effects, Mesenchymal Stem Cells cytology, Hydrogels chemistry, Hydrogels pharmacology, Hydrogels chemical synthesis, Bone Morphogenetic Protein 2 chemistry, Biocompatible Materials chemistry, Biocompatible Materials pharmacology, Biocompatible Materials chemical synthesis
- Abstract
While it is well understood that peptides can greatly improve cell-material interactions, it is often challenging to determine the concentration of the peptide which decorates a material. Herein, we describe a straightforward method using readily, synthetically accessible Fmoc peptides and commercially available reagents to measure the concentration of peptides on nanoparticles, surfaces, and hydrogels. To achieve this, the Fmoc protecting group from immobilized peptides is removed under optimized basic conditions. The dibenzofulvene released can be quantified by HPLC or UV-vis spectroscopy, enabling a direct experimental measurement of the concentration of the peptide. We show that we can measure the concentration of a BMP-2 peptide mimic on a hydrogel to determine the concentration required to stimulate osteogenesis of human mesenchymal stem cells. We envision that this methodology will enable a more thorough understanding of the concentration of synthetic peptides decorated on many biomaterials (e.g., nanoparticles, surfaces, hydrogels) to improve deconvolution of the interactions at the cell-material interface.
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- 2024
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93. Low-Level BCR::ABL1 Transcript at Diagnosis in Childhood Leukemia: A 10-Year Single Institution Study.
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Cain LE, Mirochnik O, Stevens MM, Kellie SJ, Padhye B, Keogh SJ, Govender D, Ryan J, Dalla-Pozza L, and Bateman CM
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- Humans, Child, Male, Female, Child, Preschool, Adolescent, Retrospective Studies, In Situ Hybridization, Fluorescence, Infant, Philadelphia Chromosome, Fusion Proteins, bcr-abl genetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma genetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma diagnosis, Precursor Cell Lymphoblastic Leukemia-Lymphoma pathology, Precursor Cell Lymphoblastic Leukemia-Lymphoma drug therapy
- Abstract
Introduction: Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is a high risk form of ALL associated with dismal outcomes in the pre-tyrosine kinase inhibitor (TKI) era. Addition of a TKI to chemotherapy improves outcomes. Therefore, testing for the presence of the Philadelphia chromosome by at least two methods at the time of diagnosis is critical. Diagnostic testing may include karyotype, fluorescent in situ hybridisation (FISH), and RT-PCR for the BCR::ABL1 transcript. The significance of low-level BCR::ABL1 transcript by RT-PCR in the absence of the Philadelphia chromosome on karyotype or by FISH is unknown., Methods: This is a retrospective review of children diagnosed with acute leukemia at our institution from 2010 to 2020. Those positive for the BCR::ABL1 transcript by qualitative RT-PCR, and negative for t(9;22) by karyotype or FISH were analyzed for demographics, cytogenetic and molecular features at diagnosis and relapse, treatment and outcomes. The Kaplan-Meier method was used to estimate event-free and overall survival., Results: Forty-seven of 306 (15%) patients with Ph- ALL had low-level BCR::ABL1 detected by RT-PCR. Most (77%) had B-cell ALL. The e1a2 transcript was detected most frequently, in 43 (91%) patients. BCR::ABL1 was quantifiable in 12/43 (28%) patients, with a median of 0.0008% (range 0.0003-0.095%). Seven patients (15%) relapsed. No patient with low-level BCR::ABL1 at diagnosis developed Ph + ALL at relapse. There was no difference in 5-year event-free (77% versus 81%, p = 0.407) or overall survival (86% versus 91%, p = 0.3) between children with low-level BCR::ABL1 (n = 47) and those without (n = 259)., Conclusion: BCR::ABL1 low-level positivity in children with newly diagnosed Ph- ALL is a relatively common finding and did not adversely affect outcome for patients treated using a contemporary risk-adapted approach., (© 2024 Wiley Periodicals LLC.)
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- 2024
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94. Fillable Magnetic Microrobots for Drug Delivery to Cardiac Tissues In Vitro.
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Chen MS, Sun R, Wang R, Zuo Y, Zhou K, Kim J, and Stevens MM
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- Humans, Norepinephrine pharmacology, Norepinephrine chemistry, Magnetic Fields, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Myocytes, Cardiac cytology, Drug Delivery Systems methods, Robotics, Induced Pluripotent Stem Cells cytology
- Abstract
Many cardiac diseases, such as arrhythmia or cardiogenic shock, cause irregular beating patterns that must be regulated to prevent disease progression toward heart failure. Treatments can include invasive surgery or high systemic drug dosages, which lack precision, localization, and control. Drug delivery systems (DDSs) that can deliver cargo to the cardiac injury site could address these unmet clinical challenges. Here, a microrobotic DDS that can be mobilized to specific sites via magnetic control is presented. This DDS incorporates an internal chamber that can protect drug cargo. Furthermore, the DDS contains a tunable thermosensitive sealing layer that gradually degrades upon exposure to body temperature, enabling prolonged drug release. Once loaded with the small molecule drug norepinephrine, this microrobotic DDS modulated beating frequency in induced pluripotent stem-cell derived cardiomyocytes (iPSC-CMs) in a dose-dependent manner, thus simulating drug delivery to cardiac cells in vitro. The DDS also navigates several maze-like structures seeded with cardiomyocytes to demonstrate precise locomotion under a rotating low-intensity magnetic field and on-site drug delivery. This work demonstrates the utility of a magnetically actuating DDS for precise, localized, and controlled drug delivery which is of interest for a myriad of future opportunities such as in treating cardiac diseases., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)
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- 2024
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95. Mutation and cell state compatibility is required and targetable in Ph+ acute lymphoblastic leukemia minimal residual disease.
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Winter PS, Ramseier ML, Navia AW, Saksena S, Strouf H, Senhaji N, DenAdel A, Mirza M, An HH, Bilal L, Dennis P, Leahy CS, Shigemori K, Galves-Reyes J, Zhang Y, Powers F, Mulugeta N, Gupta AJ, Calistri N, Van Scoyk A, Jones K, Liu H, Stevenson KE, Ren S, Luskin MR, Couturier CP, Amini AP, Raghavan S, Kimmerling RJ, Stevens MM, Crawford L, Weinstock DM, Manalis SR, Shalek AK, and Murakami MA
- Abstract
Efforts to cure BCR::ABL1 B cell acute lymphoblastic leukemia (Ph+ ALL) solely through inhibition of ABL1 kinase activity have thus far been insufficient despite the availability of tyrosine kinase inhibitors (TKIs) with broad activity against resistance mutants. The mechanisms that drive persistence within minimal residual disease (MRD) remain poorly understood and therefore untargeted. Utilizing 13 patient-derived xenograft (PDX) models and clinical trial specimens of Ph+ ALL, we examined how genetic and transcriptional features co-evolve to drive progression during prolonged TKI response. Our work reveals a landscape of cooperative mutational and transcriptional escape mechanisms that differ from those causing resistance to first generation TKIs. By analyzing MRD during remission, we show that the same resistance mutation can either increase or decrease cellular fitness depending on transcriptional state. We further demonstrate that directly targeting transcriptional state-associated vulnerabilities at MRD can overcome BCR::ABL1 independence, suggesting a new paradigm for rationally eradicating MRD prior to relapse. Finally, we illustrate how cell mass measurements of leukemia cells can be used to rapidly monitor dominant transcriptional features of Ph+ ALL to help rationally guide therapeutic selection from low-input samples., Competing Interests: DECLARATION OF INTERESTS S.R.M., R.J.K., M.M.S., and D.M.W. disclose equity ownership in Travera. A.K.S. reports compensation for consulting and/or SAB membership from Honeycomb Biotechnologies, Cellarity, Bio-Rad Laboratories, Fog Pharma, Passkey Therapeutics, Ochre Bio, Relation Therapeutics, IntrECate biotherapeutics, and Dahlia Biosciences unrelated to this work. P.S.W receives research funding from Microsoft. S.R. holds equity in Amgen and receives research funding from Microsoft. D.M.W. is an employee of Merck and Co., owns equity in Merck and Co., Bantam, Ajax, and Travera, received consulting fees from Astra Zeneca, Secura, Novartis, and Roche/Genentech, and received research support from Daiichi Sankyo, Astra Zeneca, Verastem, Abbvie, Novartis, Abcura, and Surface Oncology. P.S.W., A.K.S., M.A.M., S.R.M., and D.M.W. have filed a patent related to this work. Other authors – none.
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- 2024
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96. RamanSPy: An Open-Source Python Package for Integrative Raman Spectroscopy Data Analysis.
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Georgiev D, Pedersen SV, Xie R, Fernández-Galiana Á, Stevens MM, and Barahona M
- Abstract
Raman spectroscopy is a nondestructive and label-free chemical analysis technique, which plays a key role in the analysis and discovery cycle of various branches of science. Nonetheless, progress in Raman spectroscopic analysis is still impeded by the lack of software, methodological and data standardization, and the ensuing fragmentation and lack of reproducibility of analysis workflows thereof. To address these issues, we introduce RamanSPy , an open-source Python package for Raman spectroscopic research and analysis. RamanSPy provides a comprehensive library of tools for spectroscopic analysis that supports day-to-day tasks, integrative analyses, the development of methods and protocols, and the integration of advanced data analytics. RamanSPy is modular and open source, not tied to a particular technology or data format, and can be readily interfaced with the burgeoning ecosystem for data science, statistical analysis, and machine learning in Python. RamanSPy is hosted at https://github.com/barahona-research-group/RamanSPy, supplemented with extended online documentation, available at https://ramanspy.readthedocs.io, that includes tutorials, example applications, and details about the real-world research applications presented in this paper.
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- 2024
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97. Thermally Robust Solvent-Free Liquid Polyplexes for Heat-Shock Protection and Long-Term Room Temperature Storage of Therapeutic Nucleic Acids.
- Author
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Chen Y, Lin X, Liu X, Liu Y, Bui-Le L, Blakney AK, Yeow J, Zhu Y, Stevens MM, Shattock RJ, Chen R, Brogan APS, and Hallett JP
- Subjects
- Humans, Transfection methods, Polymers chemistry, Heat-Shock Response drug effects, Temperature, Hot Temperature, DNA chemistry
- Abstract
Nucleic acid therapeutics have attracted recent attention as promising preventative solutions for a broad range of diseases. Nonviral delivery vectors, such as cationic polymers, improve the cellular uptake of nucleic acids without suffering the drawbacks of viral delivery vectors. However, these delivery systems are faced with a major challenge for worldwide deployment, as their poor thermal stability elicits the need for cold chain transportation. Here, we demonstrate a biomaterial strategy to drastically improve the thermal stability of DNA polyplexes. Importantly, we demonstrate long-term room temperature storage with a transfection efficiency maintained for at least 9 months. Additionally, extreme heat shock studies show retained luciferase expression after heat treatment at 70 °C. We therefore provide a proof of concept for a platform biotechnology that could provide long-term room temperature storage for temperature-sensitive nucleic acid therapeutics, eliminating the need for the cold chain, which in turn would reduce the cost of distributing life-saving therapeutics worldwide.
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- 2024
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98. 4D Multimaterial Printing of Soft Actuators with Spatial and Temporal Control.
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Zhou K, Sun R, Wojciechowski JP, Wang R, Yeow J, Zuo Y, Song X, Wang C, Shao Y, and Stevens MM
- Abstract
Soft actuators (SAs) are devices which can interact with delicate objects in a manner not achievable with traditional robotics. While it is possible to design a SA whose actuation is triggered via an external stimulus, the use of a single stimulus creates challenges in the spatial and temporal control of the actuation. Herein, a 4D printed multimaterial soft actuator design (MMSA) whose actuation is only initiated by a combination of triggers (i.e., pH and temperature) is presented. Using 3D printing, a multilayered soft actuator with a hydrophilic pH-sensitive layer, and a hydrophobic magnetic and temperature-responsive shape-memory polymer layer, is designed. The hydrogel responds to environmental pH conditions by swelling or shrinking, while the shape-memory polymer can resist the shape deformation of the hydrogel until triggered by temperature or light. The combination of these stimuli-responsive layers allows for a high level of spatiotemporal control of the actuation. The utility of the 4D MMSA is demonstrated via a series of cargo capture and release experiments, validating its ability to demonstrate active spatiotemporal control. The MMSA concept provides a promising research direction to develop multifunctional soft devices with potential applications in biomedical engineering and environmental engineering., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)
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- 2024
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99. Modular Synthesis of Semiconducting Graft Copolymers to Achieve "Clickable" Fluorescent Nanoparticles with Long Circulation and Specific Cancer Targeting.
- Author
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Creamer A, Fiego AL, Agliano A, Prados-Martin L, Høgset H, Najer A, Richards DA, Wojciechowski JP, Foote JEJ, Kim N, Monahan A, Tang J, Shamsabadi A, Rochet LNC, Thanasi IA, de la Ballina LR, Rapley CL, Turnock S, Love EA, Bugeon L, Dallman MJ, Heeney M, Kramer-Marek G, Chudasama V, Fenaroli F, and Stevens MM
- Subjects
- Animals, Humans, Cell Line, Tumor, Polymers chemistry, Click Chemistry, Neoplasms drug therapy, Neoplasms diagnostic imaging, Neoplasms pathology, Fluorescent Dyes chemistry, Mice, Zebrafish, Nanoparticles chemistry, Polyethylene Glycols chemistry, Semiconductors, Receptor, ErbB-2 metabolism
- Abstract
Semiconducting polymer nanoparticles (SPNs) are explored for applications in cancer theranostics because of their high absorption coefficients, photostability, and biocompatibility. However, SPNs are susceptible to aggregation and protein fouling in physiological conditions, which can be detrimental for in vivo applications. Here, a method for achieving colloidally stable and low-fouling SPNs is described by grafting poly(ethylene glycol) (PEG) onto the backbone of the fluorescent semiconducting polymer, poly(9,9'-dioctylfluorene-5-fluoro-2,1,3-benzothiadiazole), in a simple one-step substitution reaction, postpolymerization. Further, by utilizing azide-functionalized PEG, anti-human epidermal growth factor receptor 2 (HER2) antibodies, antibody fragments, or affibodies are site-specifically "clicked" onto the SPN surface, which allows the functionalized SPNs to specifically target HER2-positive cancer cells. In vivo, the PEGylated SPNs are found to have excellent circulation efficiencies in zebrafish embryos for up to seven days postinjection. SPNs functionalized with affibodies are then shown to be able to target HER2 expressing cancer cells in a zebrafish xenograft model. The covalent PEGylated SPN system described herein shows great potential for cancer theranostics., (© 2023 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
100. Microneedle-mediated nanomedicine to enhance therapeutic and diagnostic efficacy.
- Author
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Zuo Y, Sun R, Del Piccolo N, and Stevens MM
- Abstract
Nanomedicine has been extensively explored for therapeutic and diagnostic applications in recent years, owing to its numerous advantages such as controlled release, targeted delivery, and efficient protection of encapsulated agents. Integration of microneedle technologies with nanomedicine has the potential to address current limitations in nanomedicine for drug delivery including relatively low therapeutic efficacy and poor patient compliance and enable theragnostic uses. In this Review, we first summarize representative types of nanomedicine and describe their broad applications. We then outline the current challenges faced by nanomedicine, with a focus on issues related to physical barriers, biological barriers, and patient compliance. Next, we provide an overview of microneedle systems, including their definition, manufacturing strategies, drug release mechanisms, and current advantages and challenges. We also discuss the use of microneedle-mediated nanomedicine systems for therapeutic and diagnostic applications. Finally, we provide a perspective on the current status and future prospects for microneedle-mediated nanomedicine for biomedical applications., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
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