Biomedical materials (Bristol, England)最新文献

Calcium phosphate-based bioscaffolds are used for bone tissue regeneration because of their physical and chemical resemblance to human bone. Calcium, phosphate, sodium, potassium, magnesium, and silicon are important components of human bone. The successful biomimicking of human bone characteristics involves incorporating all the human bone elements into the scaffold material. In this work, Mg-Whitlockite (WH) and Calcium Silicate (CS) were selected as matrix and reinforcement respectively, because of their desirable elemental composition and regenerative properties. The magnesium in WH increases mineralization in bone, and the silicon ions in CS support vascularization. The Mg-WH was synthesized using the wet chemical method, and powder characterization tests were performed. Response surface methodology (RSM) is used to design the experiments with a combination of material compositions, infill ratios (IFs), and sintering temperatures (STs). The WH/CS bioceramic composite is 3D printed in three different compositions: 100/0, 75/25, and 50/50 wt%, with IFs of 50%, 75%, and 100%. The physical and mechanical characterization study of printed samples is conducted and the result is optimized using RSM. ANOVA (Analysis of Variance) is used to establish the relationship between input parameters and responses. The optimized input parameters were the WH/CS composition of 50/50 wt%, IF of 50%, and ST of 1150 °C, which bring out the best possible combination of physical and mechanical characteristics. The RSM optimized response was a density of 2.27 g cm^-3, porosity of 36.74%, wettability of 45.79%, shrinkage of 25.13%, compressive strength of 12 MPa, and compressive modulus of 208.49 MPa with 92% desirability. The biological characterization studies were conducted for the scaffold samples prepared with optimized input parameters. The biological studies confirmed the capabilities of the WH/CS composite scaffolds in bone regenerative applications.

The search for innovative materials for manufacturing skin dressings is constant and high demand. In this context, the present study investigated the effects of a 3D printed skin dressing made of spongin-like collagen (SC) extract from marine sponge (Chondrilla caribensis), used in 3 concentrations of SC and alginate (C1, C2, C3). For this proposal, the physicochemical, morphological andin vitrobiological results were investigated. The results demonstrated that, after immersion, C2 presented a higher mass loss and C3 present a higher pH in experimental periods. Also, a higher porosity was observed for C1 and C2 skin dressings, with a higher swelling ratio for C2. For Fourier transform infrared, peaks of Amide A, -CH2, -COOH and C-O-C were seen. Moreover, the macroscopic image demonstrated a skin dressing with rough surface and grayish color that is naturally observed inChondrilla caribensis. For scanning electron microscopy analysis the presence of pores could be observed for all skin dressings, with fibers disposed in layers. Thein vitroanalyses demonstrated the viability of HFF-1 and L929 cell lines 70% of the values found for cell proliferation compared to Control Group. Furthermore, the cell adhesion analysis demonstrated that both cell lines adhered to the 3 different skin dressings and non-cytotoxicity was observed. Taking together, all the results suggest that the skin dressings are biocompatible and present non-cytotoxicity in thein vitrostudies, being considered a suitable material for tissue engineering proposals.

Hydroxyapatite (HAp) nanocoatings on titanium alloys (e.g. Ti6Al4V) have been used for prosthetic orthopaedic implants in recent decades because of their osseointegration, bioactivity, and biocompatibility. HAp is brittle with low mechanical strength and poor adhesion to metallic surfaces, which limits its durability and bioactivity. Surface modification techniques have alleviated the imperfections in biomaterials by coating the substrate. Several methods for improving the characteristics of implants, such as physical vapour deposition, the thermal spray method, the sol-gel method, microarc oxidation, and electrochemical deposition methods, have been discussed in this review. These processes provide mechanical strength without sacrificing biocompatibility and may lead to the development of new ideas for future research. This review discusses various selective additives, including carbon allotropes, ceramic materials, metallic materials, and multiple materials, to enhance tribological characteristics, biocompatibility, wear resistance, and mechanical strength. This review focuses on the fabrication of nano-HAps as coatings using selective deposition methods with controlled deposition parameters, paying special attention to recent developments in bone tissue engineering. This report is organized in such a way that it may inspire further research on surface modifications during medical treatment. The present review may help prospective investigators understand the importance of surface modifications for obtaining excellent implantation performance.

Bone morphogenetic protein 2 (BMP-2) and a polysaccharide (SUP) were embedded in the calcium phosphate cement (CPC) scaffold, and the bone repair ability was evaluated. The new scaffolds were characterized using x-ray diffraction, Fourier transform-infrared, scanning electron microscopy, and energy dispersive spectroscopy analyses. CPC-BMP2-SUPH scaffold promoted the BMP-2 release by 1.21 folds of the CPC-BMP2 scaffold on day 3. SUP sustained the release of BMP-2 within 21 d. It enhanced alkaline phosphatase activity by 25.9% in comparison to the CPC scaffold. These results suggest that the SUP consistently activated and sustained BMP-2 releasein vitro. Furthermore, the CPC-BMP2-SUPH scaffold activated the BMP-2/Smads and runt-related transcription factor 2 (Runx-2) pathways in MC3T3-E1 cells to up-regulate the levels of osteogenic relative genes (BMP-2, bone sialoprotein, collagen 1, osteocalcin, osteopontin, and Runx-2). Thein vivoresult showed that the bone defect area in the CPC-BMP2-SUPH scaffold-treated Sprague-Dawley rats lessened significantly compared with the CPC group after 4 weeks. CPC-BNP2-SUPH scaffold also improved collagen regeneration in bone. The bone surface and bone volume in the CPC-BMP2-SUPH group improved by 3.68 and 2.17-fold compared with the CPC group, respectively. In conclusion, the CPC-BMP2-SUPH scaffold represents a novel biomaterial capable of accelerating osteoblast differentiation and promoting bone injury repair.

Photothermal therapy (PTT) and photodynamic therapy (PDT) have been emerging as potential alternatives to conventional cancer treatment modalities. Gold nanoparticles, owing to their surface plasmon resonance properties, have been promising in cancer phototherapies, and extracts from potent medicinal plants are commonly employed for the green synthesis of various nanoparticles. Some researchers have used photosensitizers like chlorophyll to promote reactive oxygen species generation. In this research, the photothermal ability of gold and the photon-absorbing capability of chlorophyll derived fromSpinacia oleracea(S. oleracea) are combined to achieve the optimum results. Herein, we have synthesized the gold nanocages(AuNCs) co-assembled withS. oleraceaextract (SPAuNCs; 70 ± 10 nm) to be employed as a PTT and PDT agent to treat triple-negative breast cancer. This study found that SPAuNCs are promising PTT and PDT agents against breast cancer cell line.

Mechanical non-conformance of conventionally used transvaginal non-degradable meshes has led to complications such as organ perforation, dyspareunia caused by mesh stiffness and stress shielding. In this study, we have solved the dire need to mimic the mechanical properties of the vaginal wall by designing and developing a soft and elastic mesh made of polycaprolactone (PCL), citric acid modified polyethylene glycol (PEGC) and zinc oxide (ZnO) prepared through electrospinning and testedin vitroandin vivo. The mesh containing 90:10:0.1 of PCL, PEGC and ZnO (PEGC-15 0.1ZnO mesh) conforms to the mechanical properties of the vaginal wall of the pelvic floor, has a burst strength of ∼35 N even after gamma-sterilization and 28 d of degradation inin vitro.In vitrostudies using adipose-derived stem cells revealed that the PCL-PEGC-15 0.1ZnO meshes were biocompatible and supported higher collagen production than commercial mesh.An in vitrobacterial adhesion study showed a 2-log reduction compared to commercially available mesh for prolapse treatment. Initial biocompatibility assessment in a rabbit model also showed that the PCL-PEGC-15 0.1ZnO mesh is biocompatible and supports fibrosis throughout the mesh. The softness and flexibility of the PCL-PEGC-15 0.1ZnO mesh based onin vitrotrials and initialin vivotrials show that the mesh has a potential clinical impact for pelvic floor repair treatment.

Bioabsorbable textile scaffolds are promising for bone tissue engineering applications. Their tuneable, porous, fibre-based architecture resembles that of native extracellular matrix, and they can sustain tissue growth while being gradually absorbed in the body. In this work, immortalized mouse calvaria preosteoblast MC3T3-E1 cells were culturedin vitroon two warp-knitted bioabsorbable spacer fabric scaffolds made of poly(lactic acid) (PLA) and poly-4-hydroxybutyrate (P4HB), to investigate their osteogenic properties. Scaffold structure and yarn properties were characterized after manufacturing. Cells were seeded on the two scaffolds and treated with osteogenic media for up to 35 days. Both scaffolds supported similar cell growth patterns, featuring a higher cell density on multifilament yarns, which could be beneficial to drive cell proliferation or related phenomena in localized area of the construct. The increase in alkaline phosphatase activity and the calcium deposition observed on some PLA and P4HB scaffolds after 28 and 35 days of culture, confirm their potential to support MC3T3-E1 cells differentiation, however inconsistent mineralization was observed on the scaffolds. Due to their structural and morphological features, ability to support cell attachment and growth, and their limited osteogenic potential, these PLA and P4HB bioabsorbable textile scaffolds are recommended for further investigation for bone tissue engineering applications.

Diabetes, a chronic metabolic disease, causes complications such as chronic wounds, which are difficult to cure. New treatments have been investigated to accelerate wound healing. In this study, a novel wound dressing from fibroblast-laden atelocollagen-based hydrogel withCotinus coggygriaextract was developed for diabetic wound healing. The antimicrobial activity ofC. coggygriahexane (H), dichloromethane (DCM), dichloromethane:methanol (DCM-M), methanol (M), distilled water (DW) and traditional (T) extracts againstStaphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalisandCandida albicans, as well as their cytotoxic effects on fibroblasts were determined. While fibroblast growth was significantly (p< 0.05) promoted with DCM (121.41 ± 1.04%), M (109.40 ± 5.89%) and DW (121.83 ± 6.37%) extracts at their lowest concentrations, 2000 μg ml^-1DCM and 7.8 μg ml^-1T extracts had both non-cytotoxic and antifungal effects. An atelocollagen-based hydrogel was produced by thermal crosslinking, and its pore size (38.75 ± 7.67 μm), water content (96.63 ± 0.24%) and swelling ratio (27.21 ± 4.08%) were found to be suitable for wound dressings. A significant increase in the deoxyribonucleic acid amount (28.27 ± 1.41%) was observed in the plain hydrogel loaded with fibroblasts after 9 d of incubation, and the hydrogel had an extensively interconnected cellular network. The hydrogels containing DW and T extracts were applied to wounds generated in anin vitro3D type-2-diabetic human skin model. Although the incubation period was not sufficient for closure of the wounds in either of the treatments, the hydrogel with T extract stimulated more fibroblast migration. In the fibroblast-laden version of the hydrogel with T extract, no wound closure was observed but more keratinocytes migrated to the wound region. These positive outcomes underline the potential of the developed wound dressing as a powerful alternative to improve diabetic wound healing in clinical practice.

Coating a titanium (Ti) implant with hydroxyapatite (HA) increases its bioactivity and biocompatibility. However, implant-related infections and biological corrosion have restricted the success of implant. To address these issues, a modified HA nanocomposite (HA/silica-EDTA-AgNPs nanocomposite) was proposed to take advantage of the sustained release of silver nanoparticles (AgNPs) and silicate ions through the silica-EDTA chelating network. As a result, a uniform layer of nanocomposite, compared to HA as the gold standard, was formed on Ti implants without fracture and with a high level of adhesion, using plasma electrolytic oxidation (PEO). Bioactivity assessment evidenced a shift in the surface phase of the Ti implant to generation of beta-tricalcium phosphate, a more bioresorbable material than HA. Metabolic activity assessments using human dental pulp stem cells revealed that Ti surfaces modified by the new nanocomposite are superior to bare and HA-modified Ti surfaces for cell attachment and proliferationin vitro. In addition, it successfully inhibited bacterial growth and induced osteogenesis on the implant surface. Finally, potentiodynamic polarization behavior of Ti implants before and after coating confirmed that a thick oxide interface layer on the modified Ti surface acts as an electrical barrier and protects the substrate layer from corrosion. Therefore, the HA/silica-EDTA/Ag nanocomposite presented here, compared to HA, can better coat Ti dental implants due to its good biocompatibility and osteoinductive activity, along with improved biological stability.