11 results on '"Sekyi M"'
Search Results
2. The sensitivity of the QuantiFERON®-TB Gold Plus assay in Zambian adults with active tuberculosis
- Author
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Telisinghe, L, Amofa-Sekyi, M, Maluzi, K, Kaluba-Milimo, D, Cheeba-Lengwe, M, Chiwele, K, Kosloff, B, Floyd, S, Bailey, S-L, and Ayles, H
- Subjects
latent tuberculous infection ,Adult ,Male ,validity ,Tuberculin Test ,Sputum ,Zambia ,HIV Infections ,Original Articles ,bacterial infections and mycoses ,Sensitivity and Specificity ,Logistic Models ,Latent Tuberculosis ,Humans ,Female ,Tuberculosis, Pulmonary ,Interferon-gamma Release Tests ,interferon-gamma release assays - Abstract
SUMMARY SETTING AND OBJECTIVE: To investigate the sensitivity of the new interferon-gamma release assay (IGRA), QuantiFERON®-TB Gold Plus (QFT-Plus), for active TB (used as a surrogate for latent tuberculous infection) in a Zambian TB clinic. DESIGN: Consecutive smear or Xpert® MTB/RIF-positive adult (age ⩾18 years) pulmonary TB patients were recruited between June 2015 and March 2016. Venous blood was tested using QFT-Plus. The sensitivity was defined as the number positive divided by the total number tested. Using logistic regression, factors associated with positive QFT-Plus results were explored. RESULTS: Of 108 patients (median age 32 years, interquartile range 27–38; 73% male; 63% human immunodeficiency virus [HIV] positive), 90 were QFT-Plus-positive, 11 were negative and seven had indeterminate results; sensitivity was 83% (95%CI 75–90). There was no difference in sensitivity by HIV status (HIV-positive 85%, 95%CI 75–93; n = 68 vs. HIV-negative 80%, 95%CI 64–91; n = 40; P = 0.59). In models adjusted for age alone, CD4 cell count
- Published
- 2017
3. Evaluation of hydroxychloroquine or chloroquine for the prevention of COVID-19 (COPCOV): A double-blind, randomised, placebo-controlled trial.
- Author
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Schilling WHK, Mukaka M, Callery JJ, Llewelyn MJ, Cruz CV, Dhorda M, Ngernseng T, Waithira N, Ekkapongpisit M, Watson JA, Chandna A, Nelwan EJ, Hamers RL, Etyang A, Beg MA, Sow S, Yavo W, Allabi AC, Basnyat B, Sharma SK, Amofa-Sekyi M, Yonga P, Adler A, Yuentrakul P, Cope T, Thaipadungpanit J, Rienpradub P, Imwong M, Abdad MY, Blacksell SD, Tarning J, Goudjo FF, Dossou AD, Konaté-Touré A, Assi SB, Ouffoué K, Nasronudin N, Rachman BE, Romadhon PZ, Dewanto DD, Heryana MO, Novi T, Pasaribu AP, Mutiara M, Nasution MPR, Khairunnisa K, Dalimunthe FA, Airlangga E, Fahrezzy A, Subronto Y, Ananda NR, Rahardjani M, Rimainar A, Lucinde RK, Timbwa M, Onyango OE, Agutu C, Akech S, Hamaluba M, Kipyego J, Ngachi O, Haidara FC, Traoré OY, Diarra F, Khanal B, Dahal P, Shrestha S, Rijal S, Kabore Y, Adehossi E, Guindo O, Qamar FN, Kazi AM, Woodrow CJ, Laird S, Cheeba M, Ayles H, Cheah PY, Taylor WRJ, Batty EM, Chotivanich K, Pukrittayakamee S, Phumratanaprapin W, von Seidlein L, Dondorp A, Day NPJ, and White NJ
- Subjects
- Humans, Double-Blind Method, Female, Adult, Male, Middle Aged, Antiviral Agents therapeutic use, Antiviral Agents adverse effects, Treatment Outcome, Young Adult, Hydroxychloroquine therapeutic use, Hydroxychloroquine adverse effects, Chloroquine therapeutic use, Chloroquine adverse effects, COVID-19 Drug Treatment, COVID-19 prevention & control, COVID-19 epidemiology, SARS-CoV-2
- Abstract
Background: Hydroxychloroquine (HCQ) has proved ineffective in treating patients hospitalised with Coronavirus Disease 2019 (COVID-19), but uncertainty remains over its safety and efficacy in chemoprevention. Previous chemoprevention randomised controlled trials (RCTs) did not individually show benefit of HCQ against COVID-19 and, although meta-analysis did suggest clinical benefit, guidelines recommend against its use., Methods and Findings: Healthy adult participants from the healthcare setting, and later from the community, were enrolled in 26 centres in 11 countries to a double-blind, placebo-controlled, randomised trial of COVID-19 chemoprevention. HCQ was evaluated in Europe and Africa, and chloroquine (CQ) was evaluated in Asia, (both base equivalent of 155 mg once daily). The primary endpoint was symptomatic COVID-19, confirmed by PCR or seroconversion during the 3-month follow-up period. The secondary and tertiary endpoints were: asymptomatic laboratory-confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection; severity of COVID-19 symptoms; all-cause PCR-confirmed symptomatic acute respiratory illness (including SARS-CoV-2 infection); participant reported number of workdays lost; genetic and baseline biochemical markers associated with symptomatic COVID-19, respiratory illness and disease severity (not reported here); and health economic analyses of HCQ and CQ prophylaxis on costs and quality of life measures (not reported here). The primary and safety analyses were conducted in the intention-to-treat (ITT) population. Recruitment of 40,000 (20,000 HCQ arm, 20,000 CQ arm) participants was planned but was not possible because of protracted delays resulting from controversies over efficacy and adverse events with HCQ use, vaccine rollout in some countries, and other factors. Between 29 April 2020 and 10 March 2022, 4,652 participants (46% females) were enrolled (HCQ/CQ n = 2,320; placebo n = 2,332). The median (IQR) age was 29 (23 to 39) years. SARS-CoV-2 infections (symptomatic and asymptomatic) occurred in 1,071 (23%) participants. For the primary endpoint the incidence of symptomatic COVID-19 was 240/2,320 in the HCQ/CQ versus 284/2,332 in the placebo arms (risk ratio (RR) 0.85 [95% confidence interval, 0.72 to 1.00; p = 0.05]). For the secondary and tertiary outcomes asymptomatic SARS-CoV-2 infections occurred in 11.5% of HCQ/CQ recipients and 12.0% of placebo recipients: RR: 0.96 (95% CI, 0.82 to 1.12; p = 0.6). There were no differences in the severity of symptoms between the groups and no severe illnesses. HCQ/CQ chemoprevention was associated with fewer PCR-confirmed all-cause respiratory infections (predominantly SARS-CoV-2): RR 0.61 (95% CI, 0.42 to 0.88; p = 0.009) and fewer days lost to work because of illness: 104 days per 1,000 participants over 90 days (95% CI, 12 to 199 days; p < 0.001). The prespecified meta-analysis of all published pre-exposure RCTs indicates that HCQ/CQ prophylaxis provided a moderate protective benefit against symptomatic COVID-19: RR 0.80 (95% CI, 0.71 to 0.91). Both drugs were well tolerated with no drug-related serious adverse events (SAEs). Study limitations include the smaller than planned study size, the relatively low number of PCR-confirmed infections, and the lower comparative accuracy of serology endpoints (in particular, the adapted dried blood spot method) compared to the PCR endpoint. The COPCOV trial was registered with ClinicalTrials.gov; number NCT04303507., Interpretation: In this large placebo-controlled, double-blind randomised trial, HCQ and CQ were safe and well tolerated in COVID-19 chemoprevention, and there was evidence of moderate protective benefit in a meta-analysis including this trial and similar RCTs., Trial Registration: ClinicalTrials.gov NCT04303507; ISRCTN Registry ISRCTN10207947., Competing Interests: NJW and LvS are members of the PLOS Medicine Editorial Board. The rest of the authors have declared that no competing interests exist., (Copyright: © 2024 Schilling et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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4. The Effect of HIV on the Association of Hyperglycaemia and Active Tuberculosis in Zambia, a Case-Control Study.
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Bailey SL, Floyd S, Cheeba-Lengwe M, Maluzi K, Chiwele-Kangololo K, Kaluba-Milimo D, Amofa-Sekyi M, Yudkin JS, Godfrey-Faussett P, and Ayles H
- Subjects
- Humans, Zambia epidemiology, Case-Control Studies, Adult, Female, Male, Middle Aged, Prevalence, Young Adult, Blood Glucose analysis, Blood Glucose metabolism, Adolescent, Hyperglycemia epidemiology, Hyperglycemia blood, HIV Infections epidemiology, HIV Infections complications, HIV Infections blood, Tuberculosis epidemiology, Tuberculosis diagnosis, Tuberculosis blood
- Abstract
Objectives: To determine if HIV modifies the association between hyperglycaemia and active tuberculosis in Lusaka, Zambia., Methods: A case-control study among newly-diagnosed adult tuberculosis cases and population controls in three areas of Lusaka. Hyperglycaemia is determined by random blood glucose (RBG) concentration measured at the time of recruitment; active tuberculosis disease by clinical diagnosis, and HIV status by serological result. Multivariable logistic regression is used to explore the primary association and effect modification by HIV., Results: The prevalence of RBG concentration ≥ 11.1 mmol/L among 3843 tuberculosis cases was 1.4% and among 6977 controls was 1.5%. Overall, the adjusted odds ratio of active tuberculosis was 1.60 (95% CI 0.91-2.82) comparing those with RBG concentration ≥ 11.1- < 11.1 mmol/L. The corresponding adjusted odds ratio among those with and without HIV was 5.47 (95% CI 1.29-23.21) and 1.17 (95% CI 0.61-2.27) respectively; p-value for effect modification by HIV = 0.042. On subgroup analysis, the adjusted odds ratio of smear/Xpert-positive tuberculosis was 2.97 (95% CI 1.49-5.90) comparing RBG concentration ≥ 11.1- < 11.1 mmol/L., Conclusions: Overall, no evidence of association between hyperglycaemia and active tuberculosis was found, though among those with HIV and/or smear/Xpert-positive tuberculosis there was evidence of association. Differentiation of hyperglycaemia caused by diabetes mellitus and stress-induced hyperglycaemia secondary to tuberculosis infection is important for a better understanding of these findings., (© 2024. The Author(s).)
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- 2024
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5. Comparing patterns of recent and remote Mycobacterium tuberculosis infection determined using the QuantiFERON-TB Gold Plus assay in a high TB burden setting.
- Author
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Amofa-Sekyi M, Schaap A, Mureithi L, Kosloff B, Cheeba M, Kangololo B, Vermaak R, Paulsen R, Ruperez M, Floyd S, de Haas P, Fidler S, Hayes R, Ayles H, and Shanaube K
- Abstract
One quarter of the world's population is estimated to be infected with Mycobacterium tuberculosis. Identifying recent TB infection (TBI) offers an avenue to targeted TB preventative therapy provision, and prevention to disease progression. However, detecting recent TBI remains challenging. The QuantiFERON-TB Gold Plus assay (QFT-Plus) claims to have improved sensitivity in detecting recent TBI, by the addition of the TB2 antigen tube to the TB1 tube used in previous tests. TB2 detects CD8-mediated interferon gamma response, a potential marker of recent infection. We compared QFT-Plus TB1 and TB2 responses in individuals with recent and remote infection in high-burden settings. The Tuberculosis Reduction through Expanded Antiretroviral Treatment and TB Screening (TREATS) Project followed a cohort of adolescents and young people (AYP) aged 15-24 years in Zambia and South Africa to determine TBI incidence measured by QFT-Plus over 24 months. We categorised individuals with QTF-Plus positive result into recent and remote infection. We compared their TB1 and TB2 responses and the antigen tube differential [TB2-TB1], an indicator of CD8-activity, using logistic regression. At baseline, 3876 AYP, 1852/3876 (47.8%) were QFT-Plus positive whilst 2024/3876 (52.2%) QFT-Plus negative. Of the QFT-Plus baseline positives, 1069/1852 (57.7%) tested positive at both 12 and 24 months-remote infection. Of the QFT-Plus baseline negatives, 274/2024(13.3%) converted within a 12-month period- recent infection. TB1 and TB2 responses were higher in remote than recent infection. In recent infection, TB2 responses were greater than TB1 responses. The mean differential was 0.01 IU/ml in recent and -0.22 IU/ml in remote infection, (p = 0.145). The quantitative QFT-Plus results did not appear to reflect a marked distinction between recent and remote infection. Further analysis of the responses of infected individuals who developed disease is required to determine whether any signal in QFT-Plus results may predict progression to disease., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Amofa-Sekyi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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6. Prevalence and risk factors of M tuberculosis infection in young people across 14 communities in Zambia and South Africa.
- Author
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Amofa-Sekyi M, Schaap A, Mureithi L, Kosloff B, Cheeba M, Kangololo B, Vermaak R, Paulsen R, Ruperez M, Floyd S, de Haas P, Fidler S, Hayes R, Ayles H, and Shanaube K
- Abstract
Background: From 2018-2021 the TB Reduction through Expanded Antiretroviral Treatment and TB Screening (TREATS) project took place in 21 Zambian and South African communities. The TREATS Incidence of TB Infection Cohort Study was conducted in adolescents and young people (AYP), aged 15-24 years in 14 communities. We describe the baseline prevalence and risk factors of Mycobacterium tuberculosis (M. tuberculosis) infection among this cohort and explore the quantitative QFT-Plus interferon gamma (IFN-γ) responses., Methods and Findings: A random sample of approximately 300 AYP per community were recruited and information on TB/HIV risk factors, TB symptoms and social mixing patterns collected. QuantiFERON TB Gold Plus assay (QFT-Plus) was used to detect M. tuberculosis infection, following manufacturer's instructions. Logistic regression was used to determine factors associated with infection. 5577 eligible AYP were invited to participate across both countries, with 4648 enrolled. QFT-Plus results were available for 4529: 2552(Zambia) and 1977(South Africa). Overall, 47.6% (2156/4529) AYP had positive QFT-Plus results, the prevalence of infection in South Africa being twice that in Zambia (64.7% (1280/1977) vs 34.3% (867/2552) p<0.001). Infection was associated with age, household contact with TB and alcohol in Zambia but showed no associations in South Africa. The antigen tube differential (TB2-TB1>0.6 IU/ml) of the assay at baseline showed no evidence of association with recent TB exposure., Conclusion: The high prevalence of infection in AYP warrants urgent action to address TB control, especially in South Africa. Further research is required to delineate antigen tube responses of the QFT-Plus assay more precisely to fully realise the benefit of the additional TB2 tube in high TB/HIV burden settings., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Amofa-Sekyi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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7. The impact of a combined TB/HIV intervention on the incidence of TB infection among adolescents and young adults in the HPTN 071 (PopART) trial communities in Zambia and South Africa.
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Shanaube K, Schaap A, Mureithi L, Amofa-Sekyi M, Paulsen R, Cheeba M, Kangololo B, Vermaak R, Sisam C, Kosloff B, de Haas P, Fidler S, Ruperez M, Hayes R, Floyd S, and Ayles H
- Abstract
Background: HPTN071 (PopART) was a cluster randomized trial conducted in Zambian and South African (SA) communities, between 2013-2018. The PopART intervention (universal HIV-testing and treatment (UTT) combined with population-level TB symptom screening) was implemented in 14 communities. The TREATS study (2017-2021) was conducted to evaluate the impact of the PopART intervention on TB outcomes. We report on the impact of the combined TB/HIV intervention on the incidence of TB infection in a cohort of adolescents and young adults (AYA) aged 15-24 years., Methods: A random sample of AYA was enrolled between July 2018 and July 2019 in 7 intervention vs 7 standard-of-care communities. We collected questionnaire data on risk factors for TB, and blood for measuring TB infection using QuantiFERON (QFT) Plus. AYA were seen at months 12 and 24 with all procedures repeated. Primary outcome was incidence of TB infection comparing intervention and standard-of-care communities. An incident case was defined as a participant with QFT interferon-gamma response of < 0.2 IU/ml plasma ('negative') at baseline and a QFT interferon-gamma response of > = 0.7 IU/ml ('positive') at follow up., Results: We enrolled 4,648 AYA, 2,223 (47.8%) had a negative QFT-plus result at baseline, 1,902 (85.6%) had a follow up blood sample taken at 12 months or 24 months. Among the 1,902 AYA, followed for 2,987 person-years, 213 had incident TB infection giving (7.1 per 100 person-years). TB infection incidence rates were 8.7 per 100 person-years in intervention communities compared to 6.0 per 100 person-years in standard-of-care communities. There was no evidence the intervention reduced the transmission of TB (incidence-rate-ratio of 1.45, 95%CI 0.97-2.15, p = 0.063)., Conclusion: In our trial setting, we found no evidence that UTT combined with TB active case finding reduced the incidence of TB infection at population level. Our data will inform future modelling work to better understand the population level dynamics of HIV and TB., Competing Interests: The authors have declared that no competing interest exist., (Copyright: © 2023 Shanaube et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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8. Analogues of ERβ ligand chloroindazole exert immunomodulatory and remyelinating effects in a mouse model of multiple sclerosis.
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Karim H, Kim SH, Lauderdale K, Lapato AS, Atkinson K, Yasui N, Yamate-Morgan H, Sekyi M, Katzenellenbogen JA, and Tiwari-Woodruff SK
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- Animals, Cell Proliferation drug effects, Cell Survival drug effects, Cytokines metabolism, Estrogen Receptor beta metabolism, Female, Ligands, Male, Mice, Oligodendroglia metabolism, Oligodendroglia pathology, Corpus Callosum metabolism, Corpus Callosum pathology, Estrogen Receptor beta agonists, Immunologic Factors pharmacology, Indazoles pharmacology, Multiple Sclerosis drug therapy, Multiple Sclerosis metabolism, Multiple Sclerosis pathology, Remyelination drug effects
- Abstract
Pharmaceutical agents currently approved for the treatment of multiple sclerosis reduce relapse rates, but do not reverse or prevent neurodegeneration nor initiate myelin repair. The highly selective estrogen receptor (ER) β ligand chloroindazole (IndCl) shows particular promise promoting both remyelination while reducing inflammatory cytokines in the central nervous system of mice with experimental autoimmune encephalomyelitis. To optimize these benefits, we developed and screened seven novel IndCl analogues for their efficacy in promoting primary oligodendrocyte (OL) progenitor cell survival, proliferation, and differentiation in vitro by immunohistochemistry. Two analogues, IndCl-o-chloro and IndCl-o-methyl, induced proliferation and differentiation equivalent to IndCl and were selected for subsequent in vivo evaluation for their impact on clinical disease course, white matter pathology, and inflammation. Both compounds ameliorated disease severity, increased mature OLs, and improved overall myelination in the corpus callosum and white matter tracts of the spinal cord. These effects were accompanied by reduced production of the OL toxic molecules interferon-γ and chemokine (C-X-C motif) ligand, CXCL10 by splenocytes with no discernable effect on central nervous system-infiltrating leukocyte numbers, while IndCl-o-methyl also reduced peripheral interleukin (IL)-17. In addition, expression of the chemokine CXCL1, which is associated with developmental oligodendrogenesis, was upregulated by IndCl and both analogues. Furthermore, callosal compound action potential recordings from analogue-treated mice demonstrated a larger N1 component amplitude compared to vehicle, suggesting more functionally myelinated fibers. Thus, the o-Methyl and o-Chloro IndCl analogues represent a class of ERβ ligands that offer significant remyelination and neuroprotection as well as modulation of the immune system; hence, they appear appropriate to consider further for therapeutic development in multiple sclerosis and other demyelinating diseases.
- Published
- 2019
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9. The sensitivity of the QuantiFERON ® -TB Gold Plus assay in Zambian adults with active tuberculosis.
- Author
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Telisinghe L, Amofa-Sekyi M, Maluzi K, Kaluba-Milimo D, Cheeba-Lengwe M, Chiwele K, Kosloff B, Floyd S, Bailey SL, and Ayles H
- Subjects
- Adult, Female, Humans, Latent Tuberculosis diagnosis, Logistic Models, Male, Sensitivity and Specificity, Tuberculin Test methods, Zambia, HIV Infections epidemiology, Interferon-gamma Release Tests methods, Sputum microbiology, Tuberculosis, Pulmonary diagnosis
- Abstract
Setting and Objective: To investigate the sensitivity of the new interferon-gamma release assay (IGRA), QuantiFERON®-TB Gold Plus (QFT-Plus), for active TB (used as a surrogate for latent tuberculous infection) in a Zambian TB clinic., Design: Consecutive smear or Xpert® MTB/RIF-positive adult (age 18 years) pulmonary TB patients were recruited between June 2015 and March 2016. Venous blood was tested using QFT-Plus. The sensitivity was defined as the number positive divided by the total number tested. Using logistic regression, factors associated with positive QFT-Plus results were explored., Results: Of 108 patients (median age 32 years, interquartile range 27-38; 73% male; 63% human immunodeficiency virus [HIV] positive), 90 were QFT-Plus-positive, 11 were negative and seven had indeterminate results; sensitivity was 83% (95%CI 75-90). There was no difference in sensitivity by HIV status (HIV-positive 85%, 95%CI 75-93; n = 68 vs. HIV-negative 80%, 95%CI 64-91; n = 40; P = 0.59). In models adjusted for age alone, CD4 cell count <100 cells/μl (OR 0.15, 95%CI 0.02-0.96; P = 0.05) and body mass index <18.5 kg/m2 (OR 0.27, 95%CI 0.08-0.91; P = 0.02) were associated with decreased odds of positive QFT-Plus results., Conclusion: Overall, the sensitivity of QFT-Plus is similar to that of the tuberculin skin test and other IGRAs. While overall sensitivity is not affected by HIV status, QFT-Plus sensitivity was lower among people living with HIV/acquired immune-deficiency syndrome with severe immunosuppression.
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- 2017
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10. Two-Phase Electrospinning to Incorporate Polyelectrolyte Complexes and Growth Factors into Electrospun Chitosan Nanofibers.
- Author
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Place LW, Sekyi M, Taussig J, and Kipper MJ
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- Animals, Bone Marrow Cells cytology, Female, Humans, Immobilized Proteins chemistry, Polyvinyl Alcohol chemistry, Sheep, Stromal Cells cytology, Stromal Cells metabolism, Bone Marrow Cells metabolism, Chitosan chemistry, Electrochemical Techniques, Fibroblast Growth Factor 2 chemistry, Nanofibers chemistry, Tissue Engineering
- Abstract
Growth factors are potent signaling proteins for tissue engineering, but they are susceptible to loss of activity when exposed to solvents used for polymer processing. This work explores preservation of fibroblast growth factor-2 (FGF-2) activity in chitosan nanofibers using two-phase electrospinning via a compound coaxial needle and from a water-in-oil emulsion FGF-2 in aqueous poly(vinyl alcohol) is added on either the inside (A/O) or the outside (O/A) of an organic chitosan phase, using the compound needle. FGF-2 is further stabilized by complexation to heparin-based nanoparticles. The emulsion method does not result in detectable incorporation of FGF-2. The A/O fibers incorporate the highest amount of FGF-2. Nanoparticle-stabilized FGF-2 in A/O nanofibers is most active toward bone-marrow stromal cells., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2016
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11. Aggrecan-mimetic, glycosaminoglycan-containing nanoparticles for growth factor stabilization and delivery.
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Place LW, Sekyi M, and Kipper MJ
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- Animals, Cells, Cultured, Female, Humans, Particle Size, Recombinant Proteins chemistry, Sheep, Surface Properties, Aggrecans chemistry, Drug Delivery Systems, Fibroblast Growth Factor 2 chemistry, Glycosaminoglycans chemistry, Nanoparticles chemistry
- Abstract
The direct delivery of growth factors to sites of tissue healing is complicated by their relative instability. In many tissues, the glycosaminoglycan (GAG) side chains of proteoglycans like aggrecan stabilize growth factors in the pericellular and extracellular space, creating a local reservoir that can be accessed during a wound healing response. GAGs also regulate growth factor-receptor interactions at the cell surface. Here we report the development of nanoparticles for growth factor delivery that mimic the size, GAG composition, and growth factor binding and stabilization of aggrecan. The aggrecan-mimetic nanoparticles are easy to assemble, and their structure and composition can be readily tuned to alter their physical and biological properties. We use basic fibroblast growth factor (FGF-2) as a model heparin-binding growth factor, demonstrating that aggrecan-mimetic nanoparticles can preserve its activity for more than three weeks. We evaluate FGF-2 activity by measuring both the proliferation and metabolic activity of bone marrow stromal cells to demonstrate that chondroitin sulfate-based aggrecan mimics are as effective as aggrecan, and heparin-based aggrecan mimics are superior to aggrecan as delivery vehicles for FGF-2.
- Published
- 2014
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