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Interface phenomena refer to the phenomena caused by various physical and chemical processes occurring at phase interfaces. These phenomena can include adhesion, friction, lubrication, evaporation, condensation, adsorption, monolayer formation, and other phenomena and are applied in many fields, such as food, papermaking, rubber, material science, energy, and biomedicine. However, traditional detection equipment cannot meet the interface phenomena observation needs because the information detected by techniques such as electrochemistry, spectroscopy, chromatography, and mass spectrometry is limited, as are the sensitivity and minimum detection limit. Surface plasmon resonance (SPR) combined technology is a powerful tool for investigating interface phenomena. This paper reviews all combination technologies of SPR with various conventional detection systems, emphasizing the combination with electrochemistry, Raman spectroscopy, and mass spectrometry. These technologies can observe interface phenomena through SPR and provide redox, molecular structure, functional group change, and other information. Through this information, the reactions on the interface can be made clearer and more controllable, which plays an important role in practical detection. In the future, SPR combined technology will mainly develop toward signal enhancement, light source coupling mode, and sensor chip design, and SPR will be combined with various detection technologies to achieve real‐time in situ detection of interface phenomena. [ABSTRACT FROM AUTHOR]

Keloid scarring is an abnormal scar disease characterised by excessive proliferation of fibroblasts and over-deposition of collagen during wound healing. Although various treatments for keloid scars have been developed, preventive medicine is believed to be a promising strategy. The skin barrier limits the gentle topical administration of medicaments such as creams and hydrogel dressings, resulting in reduced therapeutic efficacy. In recent years, microneedles (MNs) have been regarded as an appreciable device for topical administration without inducing side effects, and they are painless and do not cause bleeding. In this study, an MN patch with controlled transdermal dual-drug release was developed to achieve combinatory treatment of keloid scars using a heterogeneous gelatin-structured composite MN. Gelatin hydrogel was used as a substrate to load gallic acid (GA) and quercetin-loaded amphiphilic gelatin nanoparticles to fabricate dual-drug heterogeneous composite MNs. The results of the insertion test and mechanical properties of the MNs showed that the heterogeneous composite MN patches could be self-pressed into the stratum corneum and control dual-drug release at different time periods. GA was released at an earlier stage to retard the proliferation of fibroblasts, and quercetin was released at a later stage as a strong antioxidant to erase the generation of reactive oxygen species. Furthermore, real-time quantitative polymerase chain reaction data indicated that the gene expression of fibroblasts (such as Col I and III) was downregulated in the dual-drug system. The above results demonstrate that using heterogeneous composite MNs with the combination of dual-drug pharmacology is beneficial for preventing keloid scar formation. [ABSTRACT FROM AUTHOR]

Injectable cell-based hydrogels allow surgical operation in a minimally invasive way for articular cartilage lesions but the chondrocytes in the injectable hydrogels are difficultly arrayed and fixed at the site of interest to repair the cartilage tissue. In this study, an injectable hyaluronic acid–polyacrylic acid (HA–pAA) hydrogel was first synthesized using hyaluronic acid–cyclodextrin (HA–CD) and polyacrylic acid–ferrocene (pAA–Fc) to provide cell-delivery and self-healing. To promote the cell fixation and alignment, porous poly(lactic-co-glycolic acid) (PLGA) magnetic microcapsules (PPMMs) with glutathione (GSH) loaded and iron oxide nanoparticles (IO) located in the shell were designed. The GSH-loaded PPMMs with layer-by-layer (LbL) assembly of hyaluronic acid (HA) and GSH (LbL-PPMMs) can provide a two-stage rapid and slow release of GSH to modulate the self-healing of the HA–pAA hydrogel at the injured site. Furthermore, the chondrocytes embedded in the HA–pAA hydrogel could be delivered through CD44 receptors on the HA polymer chains of LbL-PPMMs toward the surface of the damaged site by an internal magnetic force. The composite hydrogel system of chondrocytes/LbL-PPMMs/HA–pAA can provide the damaged cartilage with a more even and smooth surface than other groups in a rabbit model after 8 weeks of implantation. In addition, the chondrocytes in the deep zone tissue exhibit a columnar array, similar to the cell arrangement in normal cartilage tissue. Together with the cell navigation behavior and GSH release from the LbL-PPMM/HA–pAA hydrogel, a full closure of lesions on the cartilage tissue can be achieved. Our results demonstrate the highly promising potential of the injectable LbL-PPMM/HA–pAA system in cartilage tissue repair. [ABSTRACT FROM AUTHOR]

Extracellular matrix has an important part of the role in tissue engineering and regenerative medicine, so it is necessary to understand the various interactions between cells and extracellular matrix. Type II collagen and hyaluronic acid are the major structural components of the extracellular matrix of articular cartilage, and they are involved in fibril formation, entanglement and binding. The aim of this study was to prepare type II collagen fibrils with surface grafted with hyaluronic acid modified at the reducing end. The topographic pattern of type II collagen fibrils showed a significant change after the surface coupling of hyaluronic acid according to atomic force microscopy scanning. The presence of hyaluronic acid on the type II collagen fibrillar surface was confirmed by the specific binding of nanogold labelled with lectin. No significant increase in cell proliferation was detected by a WST-1 assay. According to histochemical examination, the maintenance of the round shape of chondrocytes and increased glycosaminoglycan secretion revealed that these cell pellets with Col II- g -hyaluronic acid molecules contained un-dedifferentiated chondrocytes in vitro. In the mixture with the 220-kDa Col II- g -hyaluronic acid copolymer, the expression of type II collagen and aggrecan genes in chondrocytes increased as demonstrated by real-time polymerase chain reaction analysis. Experimental results show that the amount of hyaluronic acid added during culturing of chondrocytes can maintain the functionality of chondrocytes and thus allow for increased cell proliferation that is suitable for tissue repair of human cartilage. [ABSTRACT FROM AUTHOR]

Highlights • A rapid-prototyping angle-scanning Surface plasmon resonance was presented. • FDM 3D printing technology was utilized to realize rapid prototyping and cost down manufacture. • Aptasensor was utilized to detect glycated hemoglobin (HbA1c) directly. • The linear detection response of HbA1c appeared in the range from 18 to 147 nM with a detection limit of 1 nM. Abstract Diabetes mellitus is one of the most common noncommunicable diseases in the world. Fasting blood glucose level is one of the diabetes diagnostic criteria, but it is readily affected by stress, exercise and many other factors. Glycated hemoglobin (HbA1c) is an important clinical index for diabetes and related diseases. In this study, a cheaper, rapid-prototyping, high-sensitivity angle-scanning surface plasmon resonance (SPR) was developed by fused deposition modeling (FDM) 3D printing technology for HbA1c detection. The sensor chip is based on an aptamer that has high affinity and high specificity to HbA1c. The results showed that this HbA1c-specific aptamer had high specificity for HbA1c, and the calculated K D was 6.13 × 10−8 M. The linear detection response of HbA1c appeared in the range of 18–147 nM, with a detection limit of 1 nM. This SPR HbA1c detection system could be a promising platform for developing clinical point-of-care diagnostic applications. [ABSTRACT FROM AUTHOR]

Due to limited self-healing capacity in cartilages, there is a rising demand for an innovative therapy that promotes chondrocyte proliferation while maintaining its biofunctionality for transplantation. Chondrocyte transplantation has received notable attention; however, the tendencies of cell de-differentiation and de-activation of biofunctionality have been major hurdles in its development, delaying this therapy from reaching the clinic. We believe it is due to the non-stimulative environment in the injured cartilage, which is unable to provide sustainable physical and biological supports to the newly grafted chondrocytes. Therefore, we evaluated whether providing an appropriate matrix to the transplanted chondrocytes could manipulate cell fate and recovery outcomes. Here, we proposed the development of electrosprayed nanoparticles composed of cartilage specific proteins, namely collagen type II and hyaluronic acid, for implantation with pre-seeded chondrocytes into articular cartilage defects. The fabricated nanoparticles were pre-cultured with chondrocytes before implantation into injured articular cartilage. The study revealed a significant potential for nanoparticles to support pre-seeded chondrocytes in cartilage repair, serving as a protein delivery system while improving the survival and biofunctionality of transplanted chondrocytes for prolonged period of time. [ABSTRACT FROM AUTHOR]

Recent studies suggest that dihydroartemisinin (DHA), a derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has anticancer properties. Due to poor water solubility, poor oral activity, and a short plasma half-life, large doses of DHA have to be injected to achieve the necessary bioavailability. This study examined increasing DHA bioavailability by encapsulating DHA within gelatin (GEL) or hyaluronan (HA) nanoparticles via an electrostatic field system. Observations from transmission electron microscopy show that DHA in GEL and HA nanoparticles formed GEL/DHA and HA/DHA aggregates that were approximately 30-40 nm in diameter. The entrapment efficiencies for DHA were approximately 13 and 35% for the GEL/DHA and HA/DHA aggregates, respectively. The proliferation of A549 cells was inhibited by the GEL/DHA and HA/DHA aggregates. Fluorescent annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining displayed low background staining with annexin V-FITC or PI on DHA-untreated cells. In contrast, annexin V-FITC and PI stains dramatically increased when the cells were incubated with GEL/DHA and HA/DHA aggregates. These results suggest that DHA-aggregated GEL and HA nanoparticles exhibit higher anticancer proliferation activities than DHA alone in A549 cells most likely due to the greater aqueous dispersion after hydrophilic GEL or HA nanoparticles aggregation. These results demonstrate that DHA can aggregate with nanoparticles in an electrostatic field environment to form DHA nanosized aggregates. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 455-462, 2014. [ABSTRACT FROM AUTHOR]

Volvox sphere is a bio-mimicking concept of an innovative biomaterial structure of a sphere that contains smaller microspheres which then encapsulate chemicals, drugs and/or cells. The volvox spheres were produced via a high-voltage electrostatic field system, using alginate as the primary material. Encapsulated materials tested in this study include staining dyes, nuclear fast red and trypan blue, and model drugs, bovine serum albumin (BSA) and cytochrome c (CytC). The external morphology of the volvox spheres was observed via electron microscopy whereas the internal structure of the volvox spheres was observed via an optical microscope with the aid of the staining dyes, since alginate is colorless and transparent. The diameter of the microspheres was about 200 to 300μm, whereas the diameter of the volvox spheres was about 1500μm. Volvox spheres were durable, retaining about 95% of their mass after 4weeks. Factors affecting entrapment efficiency, such as temperature and concentration of the bivalent cross-linker, were compared followed by a 7-day in vitro release study. The encapsulation efficiency of CytC within the microspheres was higher at cold (~4°C) and warm (~50°C) temperatures whereas temperature has no obvious effect on the BSA encapsulation. High crosslinking concentration (25% w/v) of calcium chloride has resulted higher entrapment efficiency for BSA but not for CytC. Furthermore, volvox spheres showed a different release pattern of BSA and CytC when compared to microspheres encapsulating BSA and CytC. Despite the fact that the mechanisms behind remain unclear and further investigation is required, this study demonstrates the potential of the volvox spheres for drug delivery. [ABSTRACT FROM AUTHOR]

The goal of this study was to compare the biomechanical stability of cannulated locking screws and noncannulated cortical locking screws in a periarticular locking plate. Twelve fresh-frozen porcine tibias with a 1-cm gap created distal to the tibial plateau were used to simulate an unstable proximal tibial fracture. All specimens were fixed with a periarticular proximal lateral tibial locking plate and divided into 2 groups based on whether the proximal metaphyseal screw holes of the plate were inserted with either cannulated locking screws or noncannulated cortical locking screws. An axial compressive load was applied to cause failure in each specimen using a materials testing instrument. The axial stiffness and maximum failure strength in axial loading were recorded. Axial stiffness of the constructs using noncannulated cortical locking screw was significantly higher than that of the constructs using cannulated locking screws (P=.006). Axial failure strength of the constructs using noncannulated cortical locking screw was significantly higher than that of the constructs using cannulated locking screws (P=.002). The failure mode observed in all specimens was a permanent screw-bending deformity over the head-shaft junction of proximal metaphyseal screws, irrespective of whether they were cannulated or noncannulated cortical locking screws. Fixation with noncannulated cortical locking screws offered more stability than cannulated locking screws with regard to axial stiffness and failure strength in a porcine model with unstable proximal tibial fractures. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a globally occurring articular cartilage degeneration disease that adversely affects both the physical and mental well-being of the patient, including limited mobility. One major pathological characteristic of OA is primarily related to articular cartilage defects resulting from abrasion and catabolic and proinflammatory mediators in OA joints. Although cell therapy has hitherto been regarded as a promising treatment for OA, the therapeutic effects did not meet expectations due to the outflow of implanted cells. Here, we aimed to explore the repair effect of magnetized chondrocytes using magnetic amphiphilic-gelatin nanocarrier (MAGNC) to enhance cellular anchored efficiency and cellular magnetic guidance (MG) toward the superficial zone of damaged cartilage. The results of in vitro experiments showed that magnetized chondrocytes could be rapidly guided along the magnetic force line to form cellular amassment. Furthermore, the Arg-Gly-Asp (RGD) motif of gelatin in MAGNC could integrate the interaction among cells to form cellular stacking. In addition, MAGNCs upregulated the gene expression of collagen II (Col II), aggrecan, and downregulated that of collagen I (Col I) to reduce cell dedifferentiation. In animal models, the magnetized chondrocytes can be guided into the superficial zone with the interaction between the internal magnetic field and MAGNC to form cellular stacking. In vivo results showed that the intensity of N-sulfated-glycosaminoglycans (sGAG) and Col II in the group of magnetized cells with magnetic guiding was higher than that in the other groups. Furthermore, smooth closure of OA cartilage defects was observed in the superficial zone after 8 weeks of implantation. The study revealed the significant potential of MAGNC in promoting the high-density stacking of chondrocytes into the cartilage surface and retaining the biological functions of implanted chondrocytes for OA cartilage repair. [ABSTRACT FROM AUTHOR]

An antiadhesion membrane made from gellan gum was fabricated and characterized. A 12-µm-thick membrane of gellan gum was prepared and reacted with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to obtain a cross-linked membrane (G/A70) with 87% gel content and a tensile strength of 46.5 MPa. In vivo, the G/A70 membrane had 90% less tissue adhesion. Inflammation-related and extracellular matrix protein gene expression in a rat model of abdominal surgery was found by real-time quantitative reverse transcription polymerase chain reaction analysis. On day 3, after surgery, the gene expression of ceruloplasmin and type V collagen in the G/A70-treated group was 1.9 and 0.3 times that of the control group, respectively. The G/A70 membrane elicited mild inflammation but suppressed type V collagen synthesis and reduced the occurrence of tissue adhesion. These findings provide insights into the properties of gellan gum antiadhesion membranes and help to overcome problems involving tissue adhesions in surgical procedures. [ABSTRACT FROM AUTHOR]

Scaffold architecture, including the geometry and dimension of scaffolds, is an important parameter in cell adhesion, migration, proliferation, and differentiation. Following the characterization of collagen type II nanoarchitectured molecules, collagen fibrils (CNFs) and collagen spheres (CNPs) prepared using a high-voltage electric field in our laboratory, we proposed to use these nanoarchitectured molecules to assess their influence on the culturing of chondrocytes in stirred bioreactors. The results demonstrate that chondrocytes rapidly formed more and larger chondrocyte pellets (spheroids) after the addition of nanoarchitectured molecules into the culture medium. The maintenance of chondrocytes with round morphology and increased glycosaminoglycan secretion indicated that these spheroids contained viable and un-dedifferentiated chondrocytes. No significant increases in DNA content were detected. These results show that the introduction of these molecules did not affect chondrocyte proliferation during a 3-day culture period. After the addition of CNPs and CNFs into the culture medium, the expression levels of collagen type II and aggrecan genes in chondrocytes increased significantly as demonstrated by real-time PCR analysis. Interestingly, chondrocytes exhibited distinct collagen type II and aggrecan gene expression profiles in culture with CNPs and CNFs. The aggrecan gene expression level of the chondrocytes was 2.5-fold greater following CFN addition than following the addition of CNPs. In contrast, the collagen type II expression level of the chondrocytes was 2.2-fold greater following the addition of CNPs than following the addition of CNFs. The chondrocyte pellets rapidly restored defects in articular cartilage during a 1-month implantation period in a rabbit model. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]

Background: Female breast tissue has a rich vascular supply and carries a high risk of excessive bleeding during large-core needle biopsy. It is crucial to shorten bleeding time and reduce hematoma size after the procedure. Currently, more efficient hemostatic dressings are becoming available. Material and Methods: The bleeding time and hematoma size after breast biopsy with use of either Instant Clot Pad (ICP) dressings or cotton gauze were compared. Results: ICP could attract a vast number of red blood cells and formed blood clots in about 30 s (in vitro blood clotting test). In clinical breast biopsy examinations, the average bleeding time with ICP was significantly reduced to about 2.9 min as compared to 6.4 min with cotton gauze (p < 0.005). The average hematoma size was also reduced with the use of ICP (0.89 cm3) as compared to cotton gauze (1.28 cm3). In patients with benign breast disease, ICP significantly reduced hematoma size. Conclusion: ICP used after breast biopsy could shorten the bleeding time in all patients, and significantly reduce the hematoma size in patients with benign compared to those with malignant breast disease. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Two simple in situ methods, involving the injection of a hyaluronan (HA) solution through a pair of hollow-centred parallel disc electrodes of an electrostatic field system and a micronozzle transducer of an ultrasound atomisation system, were developed and used to prepare HA microspheres in watery phase. The HA microspheres were treated by FeCl3 and 1-ethyl-3-(3-dimethyl aminopropyl) carbodimide (EDC) to secure the spherical structure shape. Depending on certain treatment conditions, the resulting series of HA microspheres exhibited good sphericity in the range of 317±22 to 579±49 µm in diameter by the electrostatic field system. Stricter conditions were needed to produce HA microspheres by the ultrasound atomisation system because of a viscosity restriction of micronozzle transducer. However, the HA microspheres could be produced and exhibited good sphericity in a smaller size under certain HA concentrations conditions. These prepared HA microspheres had various mechanical durability and could maintain their particulate shape after intra-articular administration of HA microspheres into a rabbit articular cavity for an 11-day period. [ABSTRACT FROM AUTHOR]

The article presents a study on the feasibility of chitosan and tricalcium phosphate (β-TCP) as membrane materials for guided tissue regeneration (GTR) membranes with bioabsorbable properties. The materials were supplied by Japanese firm TCI, Germany's Merck-Schuchardt, and Sigma. β-TCP is often employed as bone repairing and replacing materials due to their biocompatibility, bioactivity, and nontoxicity.

Platelet gels (PG), activated by bovine thrombin (BT), have increasingly been used in orthopedic surgery. However, BT may induce immunological reactions and carry potential viral and prion risks. To avoid these side effects, thrombin derived from human plasma (human thrombin, HT) is becoming the preferred platelet activator to prepare PG. However, limited experience and data on the clinical benefits of HT-generated PG (HTPG) in orthopedic surgery is reported. Consequently, we designed and performed a series of studies in dogs to compare the impacts of promotion of bone growth by an artificial bone substitute (Osteoset®) in combination with HTPG or without it in the spinal repair experiments. X-ray observations and histological studies were performed at predetermined periods post-operation. The preliminary results revealed the preparation of HTPG was easy and required less than 30 minutes. HTPG was capable of embedding the artificial bone substitute Osteoset® to prepare a sticky and easily manipulated composite for the application into spinal defect. We found HTPG exhibited enhancement of grafting capacity in consolidation of bone mass. After 12 weeks, tissue reconstruction reached approximately 80% of the injury defects when treated by HTPG/Osteoset® combination, but only 30∼40% in the absence of HTPG. The physiological activity of artificial bone substitute combined with PG activated by HT may therefore open beneficial prospects for more successful and safer bone formation in spine procedures in the near future. [ABSTRACT FROM AUTHOR]

The article presents a study on the application of β-calcium phosphate (TCP)/polylactide (PLA) microspheres as osteogenesis materials. For the study, researchers used the water/oil/water emulsion method for the fabrication of bioactive and biodegradable microsphere materials. They found that the microspheres showed effective repairing and recovery of the chondrocyte and osteocyte tissues in drilled defects on the condyle of New Zealand rabbits within a month.