Role of calcium phosphate and bioactive glass coating on in vivo bone healing of new Mg-Zn-Ca implant.

Present investigation focuses on development and detailed characterization of a new Mg alloy sample (BM) with and without coating of hydroxyapatite (BMH) and bioactive glass (BMG) by air plasma spray method. After detailed mechano-physico-chemical characterization of powders and coated samples, electrochemical corrosion and SBF immersion tests were carried out. Detailed in vitro characterizations for cell viability were undertaken using MG-63 cell line followed by in vivo tests in rabbit model for studying bone healing up to 60 days. Starting current density increases from BM to BMH to BMG indicating highest resistance towards corrosion in case of BMG samples, however BMH also showed highest icorr value suggesting slowest rate of corrosion than BM and BMG samples. Dissolution of calcium ion in case of BMH and BMG control formation of apatite phases on surface. Ca2+ ions of coatings and from SBF solution underwent reduction reaction simultaneously with conversion of Mg to MgCl2 releasing OH- in the solution, which increases pH. Viability and propagation of human osteoblast-like cells was verified using confocal microscopy observations and from expression of bone specific genes. Alkaline phosphatase assay and ARS staining indicate cell proliferation and production of neo-osseous tissue matrix. In vivo, based on histology of heart, kidney and liver, and immune response of IL-2, IL-6 and TNFα, all the materials show no adverse effects in body system. The bone creation was observed to be more for BMH. Although both BMH and BMG show rays of possibilities in early new bone formation and tough bone-implant bonding at interface as compared to bare Mg alloy, however, BMG showed better well-sprayed coating covering on substrate and resistance against corrosion prior implanting in vivo. Also, better apatite formation on this sample makes it more favourable implant.

Clinical Outcome of Hydroxyapatite Coated, Bioactive Glass Coated, and Machined Ti6Al4V Threaded Dental Implant in Human Jaws: A Short-Term Comparative Study.

INTRODUCTION: Growing aspect of endosseous implant research is focused on surface modification of dental implants for the purpose of improving osseointegration. The aim of this study was to evaluate and compare the clinical outcome (ie, osseointegration) of hydroxyapatite coated, bioactive glass coated and machined titanium alloy threaded dental implants in human jaw bone after implantation. MATERIALS AND METHODS: One hundred twenty-six implants (45 hydroxyapatite coated, 41 bioactive glass coated, and 40 machined titanium implants) have been placed in incisor areas of 62 adult patients. Outcome was assessed up to 12 months after prosthetic rehabilitation using different clinical and radiological parameters. Surface roughness of failed implants was analyzed by laser profilometer. DISCUSSION: Hydroxyapatite and bioactive glass coating materials were nontoxic and biocompatible. Least marginal bone loss in radiograph, significantly higher (P < 0.05) interface radiodensity, and less interfacial gaps were observed in computed tomography with bioactive glass coated implants at anterior maxilla compared to other 2 types. CONCLUSION: Bioactive glass coated implants are equally safe and effective as hydroxyapatite coated and machined titanium implants in achieving osseointegration; therefore, can be effectively used as an alternative coating material for dental implants.

Stimulated Full-Thickness Cutaneous Wound Healing with Bioactive Dressings of Zinc and Cobalt Ion-Doped Bioactive Glass-Coated Eggshell Membranes in a Diabetic Rabbit Model.

Eggshell membrane-based biomedical applications have recently received great attention for their wound-healing properties. However, there are limited studies on diabetic wound healing. In this regard, we devised four types of composite eggshell membrane mats with nanoscale coatings of bioactive glass/Zn/Co-doped bioactive glass (ESM + BAG, ESM + ZnBAG, ESM + CoBAG, and ESM + ZnCoBAG) as wound-dressing materials for chronic nonhealing diabetic wounds. A detailed study of the physicochemical properties of the mats was conducted. In vitro studies demonstrated cytocompatibility and viability of human dermal fibroblasts on all four types of mats. The cells also attached finely on the mats with the help of cellular extensions, as evident from scanning electron microscopy (SEM) and rhodamine-phalloidin and Hoechst 33342 staining of cellular components. Endowed with bioactive properties, these mats influenced all aspects of full-thickness skin wound healing in diabetic animal model studies. All of the mats, especially the ESM + ZnCoBAG mat, showed the earliest wound closure, effective renewal, and restructuring of the extracellular matrix in terms of an accurate and timely accumulation of collagen, elastin, and reticulin fibers. Hydroxyproline and sulfated glycosaminoglycans were significantly (p < 0.01, p < 0.05) higher in ESM-ZnCoBAG-treated wounds in comparison to ESM-BAG-treated wounds, which suggests that these newly developed mats have potential as an affordable diabetic wound care solution in biomedical research.

In Vitro and In Vivo Bone Regeneration Assessment of Titanium-Doped Waste Eggshell-Derived Hydroxyapatite in the Animal Model.

In this work, a titanium-doped hydroxyapatite (HAp) scaffold was produced from two different sources (natural eggshell and laboratory-grade reagents) to compare the efficacy of natural and synthetic resources of HAp materials on new bone regeneration. This comparative study also reports the effect of Ti doping on the physical, mechanical, and in vitro as well as in vivo biological properties of the HAp scaffold. Pellets were prepared in the conventional powder metallurgy route, compacted, and sintered at 900 °C, showing sufficient porosity for bony ingrowth. The physical-mechanical characterizations were performed by density, porosity evaluation, XRD, FTIR, SEM analysis, and hardness measurement. In vitro interactions were evaluated by bactericidal assay, hemolysis, MTT assay, and interaction with simulated body fluid. All categories of pellets showed absolute nonhemolytic and nontoxic character. Furthermore, significant apatite formation was observed on the Ti-doped HAp samples in the simulated body fluid immersion study. The developed porous pellets were implanted to assess the bone defect healing in the femoral condyle of healthy rabbits. A 2 month study after implantation showed no marked inflammatory reaction for any samples. Radiological analysis, histological analysis, SEM analysis, and oxytetracycline labeling studies depicted better invasion of mature osseous tissue in the pores of doped eggshell-derived HAp scaffolds as compared to the undoped HAp, and laboratory-made samples. Quantification using oxytetracycline labeling depicted 59.31 ± 1.89% new bone formation for Ti-doped eggshell HAp as compared to Ti-doped pure HAp (54.41 ± 1.93) and other undoped samples. Histological studies showed the presence of abundant osteoblastic and osteoclastic cells in Ti-doped eggshell HAp in contrast to other samples. Radiological and SEM data also showed similar results. The results indicated that Ti-doped biosourced HAp samples have good biocompatibility, new bone-forming ability, and could be used as a bone grafting material in orthopedic surgery.

Multi-ion-doped nano-hydroxyapatite-coated titanium intramedullary pins for long bone fracture repair in dogs-Clinical evaluation.

Plasma spray nano-hydroxyapatite-coated titanium intramedullary implants doped either with 5% zinc, 2.5% strontium, and 2.5% fluorine ions or with 5% zinc, 5% strontium, and 2.5% silver ions were evaluated compared with plasma spray nano-hydroxyapatite-coated titanium intramedullary implant and uncoated titanium intramedullary implants for open reduction and internal immobilization in 24 clinical cases of long bone fracture repair in dogs. Fracture-healing limb outcome was evaluated clinically, that is, radiographically. Biochemical estimation of serum calcium, serum phosphorus, alkaline phosphatase (ALP), and bone markers (bone ALP [BALP] and C-telopeptide of type 1 collagen [CTX]) was carried out on 0th day, 3rd week, 6th, and 9th week postoperatively. Multi-ion-doped plasma spray nano-hydroxyapatite-coated titanium intramedullary implants were found to be superior to plasma spray nano-hydroxyapatite-coated titanium intramedullary implants and uncoated titanium intramedullary implants in terms of all the parameters studied. Using plasma spray nano-hydroxyapatite-coated titanium implants doped with multi ions, that is, 5% zinc, 5% strontium, and 2.5% silver gave the best results in fracture repair followed by the implants doped with 5% zinc, 2.5% strontium, and 2.5% fluorine ions. Earliest and excellent limb usage with no postoperative complications was the hallmark of the use of these multi-ion-doped implants with higher serum calcium, serum phosphorus, ALP, BALP, and CTX values up to 3rd postoperative week and no lameness on the 21st day.

Engineering Vascularizing Electrospun Dermal Grafts by Integrating Fish Collagen and Ion-Doped Bioactive Glass.

Utilizing bioactive molecules from organic sources in combination with inorganic materials for enhanced tissue regeneration has been a focus of recent scientific advancements. Some recent studies showed the potential of some specialized bioactive glass for healing of soft tissues; the role of Rohu (Labeo rohita) skin-derived collagen, a biopolymer in tissue regeneration and cutaneous healing, is yet to be established. So, we have fabricated four different types of electrospun mats as wound dressing materials/dermal grafts by combining locally sourced fish (Rohu) skin-derived collagen with novel composition of bioactive glass (Fcol/BAG) without and with dopants (3% and 5% Cu and Co, respectively and their binary) aimed at achieving an accelerated wound healing. FTIR and EDX mapping indicated successful integration of collagen and ion-doped bioactive glass in electrospun mats. Microfibers' architectural features and composition provided a cytocompatible and nontoxic environment conducive to adhesion, spreading, and proliferation of human dermal fibroblasts in vitro; in addition, they were hemocompatible with rabbit red blood cells. Better cutaneous wound healing in rabbits was achieved by treating with Fcol/CoBAG and Fcol/CuCoBAG microfibers with respect to improved wound closure, well-formed continuous epidermis, higher wound maturity, and regulated deposition of extracellular matrix components; mature collagen and elastin. Notably, a significantly (p < 0.01) higher density of blood vessels/positive CD 31 staining was observed in fish collagen/ion-doped bioactive glass microfibrous mat treated wounds suggesting efficient neo-vascularization during early stages of the healing process particularly attributable to copper and cobalt ions in the doped bioactive glass. Enhanced vascularizing ability of these engineered dermal composite grafts/wound dressings along with efficient remodeling of cutaneous structural components (ECM) could collectively be ascribed to bioactive properties of bioactive glass and stimulatory roles of copper, cobalt ions, and fish collagen. Our study demonstrates that a fish collagen/Cu and Co-doped bioactive glass microfibrous mat could potentially be used as a low-cost dressing material/dermal graft for augmented cutaneous wound healing.

Copper and cobalt doped bioactive glass-fish dermal collagen electrospun mat triggers key events of diabetic wound healing in full-thickness skin defect model.

The wounds arising out of underlying hyperglycemic conditions such as diabetic foot ulcers demand a multifunctional tissue regeneration approach owing to several deficiencies in the healing mechanisms. Herein, four different types of electrospun microfibers by combining Rohu fish skin-derived collagen (Fcol) with a bioactive glass (BAG)/ion-doped bioactive glass, namely, Fcol/BAG, Fcol/CuBAG, Fcol/CoBAG, and Fcol/CuCoBAG was developed to accelerate wound healing through stimulation of key events such as angiogenesis and ECM re-construction under diabetic conditions. SEM analysis shows the porous and microfibrous architecture, while the EDX mapping provides evidence of the incorporation of dopants inside various inorganic-organic composite mats. The viscoelastic properties of the microfibrous mats as measured by a nano-DMA test show a higher damping factor non-uniform tan-delta value. The maximum ultimate tensile strength and toughness are recorded for fish collagen with copper doped bioactive glass microfibers while the least values are demonstrated by microfibers with cobalt dopant. In vitro results demonstrate excellent cell-cell and cell-material interactions when human dermal fibroblasts (HDFs) were cultured over the microfibers for 48 h. When these mats were applied over full-thickness diabetic wounds in the rabbit model, early wound healing is attained with Fcol/CuBAG, Fcol/CoBAG, and Fcol/CuCoBAG microfibers. Notably, these microfibers-treated wounds demonstrate a significantly (p < 0.01) higher density of blood vessels by CD-31 immunostaining than control, Duoderm, and Fcol/BAG treated wounds. Mature collagen deposition and excellent ECM remodeling are also evident in wounds treated with fish collagen/ion-doped bioactive glass microfibers suggesting their positive role in diabetic wound healing.

Macro-to-micro porous special bioactive glass and ceftriaxone-sulbactam composite drug delivery system for treatment of chronic osteomyelitis: an investigation through in vitro and in vivo animal trial.

A systematic and extensive approach incorporating in vitro and in vivo experimentation to treat chronic osteomyelitis in animal model were made using antibiotic loaded special bioactive glass porous scaffolds. After thorough characterization for porosity, distribution, surface charge, a novel drug composite were infiltrated by using vacuum infiltration and freeze-drying method which was subsequently analyzed by SEM-EDAX and studied for in vitro drug elution in PBS and SBF. Osteomyelitis in rabbit was induced by inoculation of Staphylococcus aureus and optimum drug-scaffold were checked for its efficacy over control and parenteral treated animals in terms of histopathology, radiology, in vivo drug concentration in bone and serum and implant-bone interface by SEM. It was optimized that 60P samples with 60-65% porosity (bimodal distribution of macro- to micropore) with average pore size ~60 µm and higher interconnectivity, moderately high antibiotic adsorption efficiency (~49%) was ideal. Results after 42 days showed antibiotic released higher than MIC against S. aureus compared to parenteral treatment (2 injections a day for 6 weeks). In vivo drug pharmacokinetics and SEM on bone-defect interface proved superiority of CFS loaded porous bioactive glass implants over parenteral group based on infection eradication and new bone formation.

Development and Characterization of Acellular Caprine Choncal Cartilage Matrix for Tissue Engineering Applications.

Because of poor regenerative capabilities of cartilage, reconstruction of similar rigidity and flexibility is difficult, challenging, and restricted. The aim of the present investigation was to develop cost-effective acellular xenogeneic biomaterial as cartilage substitution. Two novel biometrics have been developed using different chemical processes (Na-deoxycholate + SDS and GndHCl + NaOH) to decellularize caprine (goat) ear cartilage and further extensively characterized before preclinical investigation. Complete cell removal was ascertained by hematoxylin and eosin staining followed by DNA estimation. No adverse effect on extracellular matrix (ECM) was found by quantifying collagen and sulfated glycosaminoglycans (sGAG) content as well as collagen, sGAG and elastin staining. Results showed no drastic changes in ECM structure apart from desired sGAG loss. Scanning electron microscopy images confirmed cellular loss and unaltered orientation. Nano-indentation study on cartilage matrices indicated interesting output showing better results among decellularized groups. Increased elastic modulus and hardness indicated better stiffness and more active energy dissipation mechanism due to decellularization. Fluid uptake and retention property remained unchanged after decellularization as analyzed by swelling behavior study. Additionally, acellular materials were confirmed to be nonreactive and nonhemolytic as assessed by in vitro hemocompatibility study. In vivo study (up to 3 months) on rabbits showed no symptoms of graft rejection/ tissue necrosis, established through postoperative histology and biochemical analyses of tissue explants. With regard to size, shape, biomechanics, source of origin and nonimmunogenic properties, these developed materials can play versatile role in biomedical/ clinical applications and pave a new insight as alternatives in cartilage reconstruction.

Development of new localized drug delivery system based on ceftriaxone-sulbactam composite drug impregnated porous hydroxyapatite: a systematic approach for in vitro and in vivo animal trial.

PURPOSE: Present investigation deals with an extensive approach incorporating in vitro and in vivo experimentation to treat chronic osteomyelitis, using hydroxyapatite porous scaffolds. MATERIALS AND METHODS: Hydroxyapatite was synthesized in the laboratory by wet chemical method, different porous scaffolds have been fabricated. In vitro studies include variation of porosity with interconnectivity, pore-drug interfacial studies by SEM-EDAX and drug elution studies (by HPLC) both in contact with PBS and SBF at approximately 37 degrees C. In vivo trials were based on experimental osteomyelitis in rabbit model induced in tibia by Staphylococcus aureus. Characterizations included observation of histopathology, radiology and estimation of drug in both bone and serum for 42 days by HPLC method and subsequent bone-biomaterial interface by SEM. RESULTS: It was established that lower pore percentage with a distribution of mainly micro-pores were found to be superior over the higher pore percentage both in vitro and in vivo. The criteria was matched with the 50N50H samples which had 50-55% porosity with an average pore size approximately 110 microm, having higher interconnectivity (10-100 microm), moderately high adsorption efficiency (approximately 50%) when loaded with CFS (drug combinations consisting of irreversible b-lactamase inhibitor and b-lactam antibiotic). CFS release from HAp implants were faster in PBS than SBF. Further, both the results of in vitro and in vivo drug elution after 42 days showed release higher than minimum inhibitory concentration of CFS against Staphylococcus aureus. In vivo studies also proved the superiority of CFS loaded HAp implants than parenteral group based on eradication of infection and new bone formation. CONCLUSIONS: HAp based porous scaffold loaded with CFS and designed porosity (in terms of micro- and macro-porosity, interconnectivity) was found to be an ideal delivery system which could locally, sustainably release the composite antibiotic in reliable manner both in terms of in vitro drug elution behaviour in contact with SBF and in vivo animal trial.

Porous bioactive glass scaffolds for local drug delivery in osteomyelitis: development and in vitro characterization.

A new bioactive glass-based scaffold was developed for local delivery of drugs in case of osteomyelitis. Bioactive glass having a new composition was prepared and converted into porous scaffold. The bioactivity of the resulting scaffold was examined by in vitro acellular method. The scaffolds were loaded with two different drugs, an antibacterial or antifungal drug. The effects of the size of the scaffold, drug concentration, and dissolution medium on drug release were studied. The scaffolds were further coated with a degradable natural polymer, chitosan, to further control the drug release. Both the glass and scaffold were bioactive. The scaffolds released both the drugs for 6 weeks, in vitro. The results indicated that the bigger the size and the higher the drug concentration, the better was the release profile. The scaffolds appeared to be suitable for local delivery of the drugs in cases of osteomyelitis.

Mesoporous bioactive glasses for bone healing and biomolecules delivery.

Impact of bone diseases and injury is increasing at an enormous rate during the past decades due to increase in road traffic accidents and other injuries. Bioactive glasses have excellent biocompatibility and osteoconductivity that makes it suitable for bone regeneration. Researches and studies conducted on several bioactive glasses gives an insight on the need of multi-disciplinary approaches involving various scientific fields to attain its full potential. Of late, a next generation bioactive glass called as mesoporous bioactive glass (MBG) has been developed with higher specific surface area and control over mesoporous structure that presents a new material for bone regeneration. A brief discussion and overview on the potential use of MBG as a suitable material for bone tissue regeneration and biomolecule delivery is included. Additionally, possible control of the structural and functional property based on composition and fabrication techniques are also covered. According to recent researches, MBG-implant interaction with bone forming cells for cellular growth and differentiation as well as its effect on delivery of growth factor, both in vitro and in vivo, are optimistic; yet, the complete efficacy of this material is still to be explored. Hence, in this article we will review the current development and its applications for bone tissue engineering (TE).

Mechanical behaviour of additively manufactured bioactive glass/high density polyethylene composites.

Bioactive glass (BAG) is a well-known biomaterial that can form a strong bond with hard and soft tissues and can also aid in bone regeneration. In this study, BAG is added to a polymer to induce bioactivity and to realize fused filament fabrication (FFF) based printing of polymer composites for potential orthopaedic implant applications. BAG (5, 10, and 20 wt%) is melt compounded with high density polyethylene (HDPE) and subsequently extruded into feedstock filament for FFF-printing. Tensile tests on developed filaments reveal that they are stiff enough to resist forces exerted during the printing process. Micrography of printed HDPE/BAG reveals perfect diffusion of raster interface indicating proper selection of printing parameters. Micrography of freeze fractured prints shows the homogeneous distribution and good dispersion of filler across the matrix. The tensile, flexural, and compressive modulus of FFF-printed HDPE/BAG parts increases with filler addition. BAG addition to the HDPE matrix enhances flexural and compressive strength. The tensile and flexural behaviour of FFF-prints is comparable to injection molded counterparts. Property maps exhibit the merits of present study over the existing literature pertaining to desired bone properties and polymer composites used in biomedical applications. It is envisioned that the development of HDPE/BAG composites for FFF-printing can lead to possible orthopaedic implants and scaffolds to mimic the bone properties in customised anatomical sites or injuries.

Probing the Influence of γ-Sterilization on the Oxidation, Crystallization, Sliding Wear Resistance, and Cytocompatibility of Chemically Modified Graphene-Oxide-Reinforced HDPE/UHMWPE Nanocomposites and Wear Debris.

Osteolysis and aseptic loosening due to wear at the articulating interfaces of prosthetic joints are considered to be the key concerns for implant failure in load-bearing orthopedic applications. In an effort to reduce the wear and processing difficulties of ultrahigh-molecular-weight polyethylene (UHMWPE), our research group recently developed high-density polyethylene (HDPE)/UHMWPE nanocomposites with chemically modified graphene oxide (mGO). Considering the importance of sterilization, this work explores the influence of γ-ray dosage of 25 kGy on the clinically relevant performance-limiting properties of these newly developed hybrid nanocomposites in vitro. Importantly, this work also probes into the cytotoxic effects of the wear debris of different compositions and sizes on MC3T3 murine osteoblasts and human mesenchymal stem cells (hMSCs). In particular, γ-ray-sterilized 1 wt % mGO-reinforced HDPE/UHMWPE nanocomposites exhibit an improvement in the oxidation index (16%), free energy of immersion (-12.1 mN/m), surface polarity (5.0%), and hardness (42%). Consequently, such enhancements result in better tribological properties, especially coefficient of friction (+13%) and wear resistance, when compared with UHMWPE. A spectrum of analyses using transmission electron microscopy (TEM) and in vitro cytocompatibility assessment demonstrate that phagocytosable (0.5-4.5 µm) sterilized 1 mGO wear particles, when present in culture media at 5 mg/mL concentration, induce neither significant reduction in MC3T3 murine osteoblast and hMSC growth nor cell morphology phenotype, during 24, 48, and 72 h of incubation. Taken together, this study suggests that γ-ray-sterilized HDPE/UHMWPE/mGO nanocomposites can be utilized as promising articulating surfaces for total joint replacements.

Synthesis and characterization of PCL-DA:PEG-DA based polymeric blends grafted with SMA hydrogel as bio-degradable intrauterine contraceptive implant.

Presently available long-acting reversible female contraceptive implants are said to be an effective way of preventing unintended pregnancy. Unacceptable side effects attributed by these contraceptive implants act as a major drawback for the practitioners. These problems pave the way for the development of a new form of long-acting non-hormonal female contraceptive implant, especially in the developing countries. PCL-DA: PEG-DA polymeric scaffold is grafted with Styrene Maleic Anhydride (SMA) based hydrogel, and their physicochemical, thermal and biological parameters are being explored for developing a bio-degradable form of the non-hormonal intrauterine contraceptive implant. With the fixed ratio of PEG-DA: PCL-DA polymer, SMA hydrogel was added at four different concentrations to determine the optimum concentration of SMA hydrogel for the development of a promising long-acting biodegradable intrauterine contraceptive implant. Structural elucidation of the polymers was confirmed using 1H and 13C NMR spectroscopic analyses. The physiochemical characterization report suggests that SMA hydrogel interacts with the PCL-DA: PEG-DA polymeric scaffold through intermolecular hydrogen bonding interaction. The in-vitro spermicidal activity of the polymeric scaffold increases when the concentration of SMA based hydrogel in the polymer samples is increased without showing any significant toxicological effects. From the study results, it may be concluded that SMA hydrogel grafted PCL-DA: PEG-DA scaffold can be developed as intra-uterine biodegradable non-hormonal female contraceptive implant due to its excellent bio-compatibility and spermicidal activity.

Development of nano-porous hydroxyapatite coated e-glass for potential bone-tissue engineering application: An in vitro approach.

To reconstruct the defects caused by craniectomies autologous, bone grafting was usually used, but they failed most commonly due to bone resorption, infections and donor-site morbidity. In the present investigation, an effort has been made for the first time to check the feasibility and advantage of using hydroxyapatite (HAp) coated e-glass as component of bone implants. Sol-gel synthesized coatings were found to be purely hydroxyapatite from XRD with graded and interconnected pores all over the surface observable in TEM. The interconnected porous nature of ceramics are found to increase bioactivity by acting to up-regulate the process of osseointegration through enhanced nutrient transfer and induction of angiogenesis. From TEM studies and nano indentation studies, we have shown that pores were considered to be appropriate for nutrient supply without compromising the strength of sample while in contact with physiological fluid. After SBF immersion test, porous surface was found to be useful for nucleation of apatite crystals, hence increasing the feasibility and bioactivity of sample. However, our quasi-dynamic study showed less crystallization but had significant formation of apatite layer. Overall, the in vitro analyses show that HAp coated e-glass leads to significant improvement of implant properties in terms of biocompatibility, cell viability and proliferation, osteoinductivity and osteoconductivity. HAp coating of e-glass can potentially be utilized in fabricating durable and strong bioactive non-metallic implants and tissue engineering scaffolds.

The repair of segmental bone defects with porous bioglass: an experimental study in goat.

This study was exclusively conducted to evaluate healing of surgically created defects on the radius of adult Black Bengal goat after implantation of porous bioglass blocks and compare the process kinetics with normal healing. Twelve Black Bengal goats were divided randomly into two groups: control and experimental group implanted with bioglass blocks. Unicortical bone defects in radius were generated in all animals under aseptic condition. Local inflammatory reaction and healing of wound, radiological investigations, histological studies, oxytetracycline leveling and angiographic studies were performed up to 90th day post-operatively and compared with normal healing. It has been found that extensive new bone formation originating from host bone towards the implant whereas in control, the process was active from both the ends; the defect site appeared as homogenous nonfluorescent area. Thus, porous bioglass promoted bone formation over the entire extension of the defect independent of size of block in comparison to control group.

Mechanical and in vitro degradation behavior of magnesium-bioactive glass composites prepared by SPS for biomedical applications.

In order to make magnesium (Mg) a successful candidate for fracture fixation devices, it is imperative to control the corrosion rate and enhance its elastic modulus. In the present work, we have prepared bioactive glass (BG) reinforced magnesium composite using spark plasma sintering (SPS). Simultaneous application of heat and pressure during SPS decreased the softening point of BG (600°C), allowing it to coat the Mg particles partially. As a result, BG was found along the Mg particle boundaries, which was confirmed by elemental mapping. Addition of BG improved microhardness and elastic modulus of Mg-BG composites. Corrosion behavior was studied by hydrogen evolution and immersion corrosion in phosphate buffered saline (PBS). After 64 h of immersion, Mg-10 wt % BG composite showed highest corrosion resistance. Quantitative micro-computed tomography (micro-CT) results indicated porosity increase in Mg-BG composites during immersion. The maximum increase in porosity (1.66%) was noticed for pure Mg while the minimum for Mg-10 wt % BG composite. MG63 cell-material interactions, using extract method, showed good cytocompatibility for Mg-10 wt % BG composite. The concentration of Mg ion in cell culture media was measured using atomic absorption spectroscopy after 24 h immersion of Mg/BG composites. The results indicated that using BG as reinforcement and SPS as sintering method; we can prepare corrosion resistant and high modulus Mg-BG composites that can be used for fabricating bone fracture fixation plates. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 352-365, 2019.

Potential of growth factor incorporated mesoporous bioactive glass for in vivo bone regeneration.

Mesoporous bioactive glass (MBG) has drawn much attention due to its superior surface texture, porosity and bioactive characteristics. Aim of the present study is to synthesize MBG using different surfactants, viz., hexadecyltrimethylamonium(CTAB) (M1), poly-ethylene glycol (PEG) (M2) and pluronic P123 (M3); bioactivity study; and to understand their bone regeneration efficacy in combination with insulin-like growth factors (IGF-1) in animal bone defect model. SBF study revealed the formation of calcium carbonate (CaCO3) and hydroxyapatite (HAp) phase over 14 days. Formation of apatite layer was further confirmed by FTIR, FESEM and EDX analysis. M1 and M2 showed improved crystallinity, while M3 showed slightly decrease in crystalline peak of CaCO3 and enhanced HAp phase. More Ca-P layer formed in M1 and M2 supported the in vivo experiments subsequently. Degree of new bone formation for all MBGs were high, i.e., M1 (80.7 ±â€¯2.9%), M2 (74.4 ±â€¯2.4%) and M3 (70.1 ±â€¯1.9%) compared to BG (66.9 ±â€¯1.8%). In vivo results indicated that the materials were non-toxic, biodegradable, biocompatible, and is suitable as bone replacement materials. Thus, we concluded that growth factor loaded MBG is a promising candidate for bone tissue engineering application.

Preparation and in vivo biocompatibility studies of different mesoporous bioactive glasses.

A new generation of nanostructured glasses called mesoporous bioactive glasses (MBGs) exhibit superior surface texture, porosity and bioactive characteristics. The present study is carried out to develop and detailed characterize of ternary SiO2-CaO-P2O5 MBG structure, fabricated by three different variations using different surfactants, e.g., hexadecyltrimethylammonium bromide (CTAB), poly-ethylene glycol,(PEG) and Pluronic P123. After thorough physico-chemical characterization, MBG granules were investigated for in vivo bone regeneration in animal bone defect model (rabbit) where standard S53P4 bioactive glass was used as control. All the synthesized MBG powders showed nano-range median particle size of 80-120 nm (MBG-CTAB), 50-70 nm (MBG-PEG and MBG-P123) while their specific surface area as 473.2, 52.2 and 169.3 m2/g respectively. All MBGs showed mesoporous nature corroborating transmission electron microscopy (TEM) observation as well. Bone regeneration property was measured after 45 and 90 days post-implantation at distal epiphysis of rabbit femur by radiography, histology, fluorochrome labeling, micro computed tomography (micro-CT) and vital organ histology. Results from in vivo studies indicated that the MBG materials produce minimal toxicity to the body. Furthermore, the biocompatibility and biodegradability of the implant makes them more suitable for application in bone tissue engineering. Among various implants, MBG fabricated using suitable surfactant (CTAB) shown the best result compared to other implants. Nonetheless, all the materials are suitable for application in bone tissue engineering and have potential for bone regeneration and healing.