Collagen Hydroxyapatite Research Articles

Treatment of Juvenile Knee Osteochondritis Dissecans with a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and MRI Results at Mid-Term Follow-up.

Osteochondral surgical procedures have been described for the treatment of unfixable osteochondritis dissecans (OCD), but only few of them have been studied for juvenile OCD (JOCD) lesions. A cell-free biomimetic osteochondral scaffold showed positive results in adult patients. The aim of this study was to evaluate the results of this scaffold for the treatment of knee JOCD at mid-term follow-up. Twenty patients (14 males, 6 females) were included in this study. Mean age was 16.2 ± 1.4 years, average defect size was 3.2 ± 1.8 cm2, and mean symptoms duration was 20.2 ± 17.9 months. After the implantation of the osteochondral collagen-hydroxyapatite scaffold (Maioregen, Fin-Ceramica, Faenza, Italy), patients were evaluated preoperatively and prospectively at 1, 2, and at final mean follow-up of 6 years (range 5-7 years) with International Knee Documentation Committee (IKDC) subjective and objective, Tegner, and EuroQol visual analogue scale (VAS) scores. MRI evaluation was performed with the MOCART 2.0 score. All scores showed a significant improvement. IKDC subjective score went from 50.3 ± 17.4 preoperative score to 75.3 ± 14.6 at 1 year (P = 0.002), 80.8 ± 14.6 at 2 years and 85.0 ± 9.3 at 6 years. The Tegner score improved from the preoperative evaluation of 2.6 ± 1.4 to 5.5 ± 2.0 at 6 years (P < 0.0005), although without reaching the level registered before the onset of symptoms. A longer symptoms duration influenced negatively IKDC subjective and Tegner scores up to 2 years (P = 0.003 and P = 0.002, respectively) but did not affect the final outcome. Lesion size did not affect the final result. The MOCART 2.0 score showed a significant improvement between 1-year and final follow-up, but with persisting subchondral alterations. This study demonstrated a clinical improvement stable over time with a high survival rate, although with persisting abnormal MRI findings, especially at subchondral bone level. This procedure can be considered a suitable option for the treatment of young patients affected by knee OCD. Level of evidence. Case series, level IV.

A comparative study of polycaprolactone–hydroxyapatite scaffold and collagen membrane carriers for recombinant human bone morphogenic protein-2 for guided bone regeneration

The polycaprolactone-30% hydroxyapatite (PCL-30%HA) scaffolds were fabricated using Melt Stretching and Multilayer Deposition (MSMD) technique. Different models of guided bone regeneration were evaluated in rat models. Group A, the calvarial defects were covered with collagen membranes. Group B, the scaffolds were placed into the defects and covered with the membranes. 200 µL of the 400 µg/mL BMP solution was slowly dripped onto the membranes. Group C, the scaffolds were soaked in the BMP solution before being placed. Group D, only the scaffolds were placed. Conclusively, the Group C model could enhance new bone formation better than the other models.

Effect of mesenchymal stem cell-incorporated hydroxyapatite-collagen scaffold on tissue repair in acute spinal cord injury, and the mechanism involved

Purpose: To study the effect of hydroxyapatite-collagen (HC) scaffold with mesenchymal stem cells (MSCs) on tissue repair in acute spinal cord injury (SCI).Method: Adult female Sprague-Dawley rats weighing 200 - 230 g were randomly divided into two groups implanted either with bone marrow-MSCs (experimental group) or HC scaffold alone (control group). Spinal cord injury was induced using laminectomy, resulting in a 2.0-mm gap at T10 of the spinal cord. The gap was filled in both groups with 2-mm HC scaffold at day 10 of culture. Cellular development, viability, and proliferation inside the scaffold were determined. Angiogenesis was determined by measuring fibronectin (FN) immunofluorescence, von Willebrand factor (vWF), hypoxiainducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF).Results: HC scaffold strengthened MSCs. Bone marrow MSCs exhibited no statistically significant difference when compared with cells in culture at day 10 (47.03 ± 3.135 %, p &gt; 0.05). Moreover, on days 5 and 10, FN deposition was higher in MSCs with scaffold than in scaffold-free MSCs. The expressions of FN, vWF, HIF-1α and VEGF were positively correlated, indicating that incorporation of HC scaffold into MSCs significantly improved tissue repair by improving angiogenesis via a differentiation process (p &lt; 0.001).Conclusion: These findings suggest that HC scaffold with MSCs is a potential therapeutic procedure for spinal cord injury.&#x0D; Keywords: Mesenchymal stem cells, Hydroxyapatite-collagen, Spinal cord injury, HC scaffold

Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration

AbstractThe synthesis of collagen–hydroxyapatite composites has been carried out, and the biocompatibility and osteoconductivity properties have been tested. This research was conducted to determine the ability of hydroxyapatite–collagen composites to support the bone growth through the graft surface. Hydroxyapatite used in this study was synthesized from coral with a purity of 96.6%, while collagen was extracted from the chicken claw. The process of forming a scaffold of collagen–hydroxyapatite composites was carried out using the freeze-drying method at −80°C for 4 h. The biocompatibility characteristics of the sample through the cytotoxicity tests showed that the percentage of viable cells in collagen–hydroxyapatite biocomposite was 108.2%, which is higher than the percentage of viable cells of hydroxyapatite or collagen material. When the viable cell is above 100%, collagen–hydroxyapatite composites have excellent osteoconductivity as a material for bone regeneration.

Osteogenic Potential of 3-D printed Multilayered Poly L-lactic Acid (PLLA) Scaffold on the Healing of Critical-sized Bone Defect in Dogs

Critical sized bone defect is a major challenge for orthopedic surgeons. These defects result following any pathologic condition leading to massive bone loss. Synthetic and biological based tissue engineered biomaterials and their combinations provide a promising substitute to fill the defect site. The aim of the present study was to evaluate the osteogenic potential of 3-D printed multilayered medical grade PLLA scaffold with collagen and nano hydroxyapatite for the healing of induced critical-sized bone defect in dogs. An experimental study was conducted on 12 skeletally mature male dogs. Critical defect (25mm) was induced into the right femur of all dogs. Dogs were randomly allocated into one of the following groups (4 dogs/group). PLLA scaffold seeded with nano hydroxyapatite and collagen molded on the defect (PLLA/Collagen/nHA group), the second group; the defect seeded with collagen and nano hydroxyapatite (Collagen/nHA group), the third one was left without scaffold or additives (Sham operated group), and the operated animals were left for 12 weeks. Animals were evaluated clinically, radiographically and histopathologicaly. In (PLLA/Collagen/nHA group), all dogs showed an improvement in lameness degree from sever to apparently free from lameness. Radiography showed newly formed bone filling the defect with no inter zone. Histopathology showed more maturation of the newly formed bone in the defect site had occurred as well as defined bone trabeculae in comparing to other groups. In conclusion, 3D printed multilayered medical grade PLLA with collagen and nano hydroxyapatite provide biodegradable osteoconductive scaffold for enhancing the healing of critical sized bone defect.

Fabrication of High-Strength and Porous Hybrid Scaffolds Based on Nano-Hydroxyapatite and Human-Like Collagen for Bone Tissue Regeneration.

A novel, three-dimensional, porous, human-like collagen (HLC)/nano-hydroxyapatite (n-HA) scaffold cross-linked by 1,2,7,8-diepoxyoctane (DEO) was successfully fabricated, which showed excellent mechanical and superior biological properties for bone tissue regeneration in this study. The physicochemical characterizations of different n-HA/HLC/DEO (nHD) scaffolds were investigated by determining the morphology, compression stress, elastic modulus, Young’s modulus and enzymatic hydrolysis behavior in vitro. The results demonstrated that nHD-2 and nHD-3 scaffolds showed superior mechanical properties and resistance to enzymatic hydrolysis compared to nHD-1 scaffolds. The cell viability, live cell staining and cell adhesion analysis results demonstrated that nHD-2 scaffolds exhibited low cytotoxicity and excellent cytocompatibility compared with nHD-1 and nHD-3 scaffolds. Furthermore, subcutaneous injections of nHD-2 scaffolds in rabbits produced superior anti-biodegradation effects and histocompatibility compared with injections of nHD-1 and nHD-3 scaffolds after 1, 2 and 4 weeks. In addition, the repair of bone defects in rabbits demonstrated that nHD-2 scaffolds presented an improved ability for guided bone regeneration and reconstruction compared to commercially available bone scaffold composite hydroxyapatite/collagen (HC). Collectively, the results show that nHD-2 scaffolds show promise for application in bone tissue engineering due to their excellent mechanical properties, anti-biodegradation, anti-biodegradation, biocompatibility and bone repair effects.

Biomimetic gradient scaffold of collagen–hydroxyapatite for osteochondral regeneration

Osteochondral defects remain a major clinical challenge mainly due to the combined damage to the articular cartilage and the underlying bone, and the interface between the two tissues having very different properties. Current treatment modalities have several limitations and drawbacks, with limited capacity of restoration; however, tissue engineering shows promise in improving the clinical outcomes of osteochondral defects. In this study, a novel gradient scaffold has been fabricated, implementing a gradient structure in the design to mimic the anatomical, biological and physicochemical properties of bone and cartilage as closely as possible. Compared with the commonly studied multi-layer scaffolds, the gradient scaffold has the potential to induce a smooth transition between cartilage and bone and avoid any instability at the interface, mimicking the natural structure of the osteochondral tissue. The scaffold comprises a collagen matrix with a gradient distribution of low-crystalline hydroxyapatite particles. Physicochemical analyses confirmed phase and chemical compositions of the gradient scaffold and the distribution of the mineral phase along the gradient scaffold. Mechanical tests confirmed the gradient of stiffness throughout the scaffold, according to its mineral content. The gradient scaffold exhibited good biological performances both in vitro and in vivo. Biological evaluation of the scaffold, in combination with human bone-marrow–derived mesenchymal stem cells, demonstrated that the gradient of composition and stiffness preferentially increased cell proliferation in different sub-regions of the scaffold, according to their high chondrogenic or osteogenic characteristics. The in vivo biocompatibility of the gradient scaffold was confirmed by its subcutaneous implantation in rats. The gradient scaffold was significantly colonised by host cells and minimal foreign body reaction was observed. The scaffold’s favourable chemical, physical and biological properties demonstrated that it has good potential as an engineered osteochondral analogue for the regeneration of damaged tissue.

Bone regeneration is enhanced by the combined use of acid-electrolyzed functional water with hydroxyapatite/collagen composite.

Hydroxyapatite/collagen (HAP/Col) composite has a nanostructure and composition similar to that of natural bone. Herein, we have evaluated the beneficial effects of acid-electrolyzed functional water (FW) in combination with HAP/Col composite as an irrigation material in a rat calvarium defect model. The rats were divided into four groups: control, PBS irrigation; FW, FW irrigation; HAP/Col, filled with HAP/Col; FW + HAP/Col, FW irrigation prior to HAP/Col filling. Bone volume (BV) and bone mineral density (BMD) of the newly formed bone were analyzed by microcomputed tomography. The results indicated that the combined use of FW and HAP/Col significantly augmented both BV (12.25 ± 1.93 mm3 , control: 3.22 ± 0.55 mm3 , 6 weeks) and BMD (120.09 ± 14.76 cm3 /mg vs. control: 54.67 ± 7.20 cm3 /mg, 6 weeks) in a time-dependent manner, which might be attributed to the soluble factor-inducing ability of FW. Based on this assumption, bFGF concentration in peripheral blood was measured. bFGF concentration was significantly increased in the FW + HAP/Col group (68.25 ± 9.2 pg/ml vs. control: 21.70 ± 8.18 pg/ml, 6 hr). Real-time PCR demonstrated significant augmentation of MCSF (2.82 ± 0.59-fold), RANKL (2.51 ± 0.33-fold) and BMP7 (1.66 ± 0.25-fold) (bone regeneration-related genes) and PDGF (1.31 ± 0.15-fold), VEGF (3.27 ± 0.42-ld) and IL-8 (6.77 ± 2.02-fold) (angiogenic genes) mRNAs in the FW + HAP/Col group. Taken together, these results suggest that the combined use of FW and HAP/Col induces bone regeneration, presumably by inducing the factors contributing to bone regeneration and angiogenesis.

Hydroxyapatite-collagen augments osteogenic differentiation of dental pulp stem cells.

The objectives of this study were to isolate and culture dental pulp stem cells (DPSCs) and to investigate their proliferation and osteogenic differentiation on hydroxyapatite-collagen (HA-Col) scaffold. DPSCs were characterized by fluorescence-activated cell sorting (FACS). Cultured cells were CD73+, CD90+, CD105+ and CD31-, CD45-. A commercially available HA-Col scaffold was used for culture of DPSCs. Cell attachment and viability of DPSCs cultured on scaffold was studied by sulforhodamine assay. Osteoblast differentiation capacity was studied by alkaline phosphatase assay and the effects of growth factors such as PDGF, IGF1 and FGF2 were further studied. Scanning electron microscopy (SEM) of cell seeded scaffolds was also performed. We found that DPSCs cultured exhibited the characteristic mesenchymal stem cells (MSCs) morphology and differentiation properties. Scaffold was found to be non-cytotoxic and had good biocompatibility in vitro. Osteoblast differentiation ability was found to increase at higher concentration of scaffold and additive effects were observed with the use of growth factors. In SEM, cells appeared to cover the entire surface of the scaffold forming continuous cell layer and extending filopodial extensions. HA-Col scaffold is apt for MSCs attachment and proliferation in vitro. Their unique self-renewal and multilineage differential potential make them ideal for use in regenerative medicine. The limitations of currently available bone graft materials have led to the emergence of tissue engineering using mesenchymal stem cells (MSCs). Since, HA-Col scaffold potentiated the proliferation and osteogenic differentiation of DPSCs, this biomimetic material may be an ideal one for maxillofacial and alveolar bone regeneration.

Hydroxyapatite-Collagen Composite Made from Coral and Chicken Claws for Bone Implant Application

Synthesis of porous hydroxyapatite-collagen composites for bone implant applications has been carried out. Hydroxyapatite synthesized from coral by the precipitation method, while Collagen synthesized from chicken claws. Collagen formation was carried out by freeze-dry technique with variations in freezing time of 2, 4 and 6 hours at -80 ° C. The next process was by drying in a lyophilizer. Characterization of samples was carried out using Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy (SEM), compressive strength test and cytotoxicity test with Microtetrazolium (MTT) assay. FTIR results proved that collagen uptake and hydroxyapatite combine chemically. This is indicated by the absorption of functional groups that did not coincide between collagen and hydroxyapatite functional groups with composites. SEM observations showed that the largest pore size was obtained at freezing for 2 hours which was 774 μm and the smallest in freezing for 6 hours was 640 μm. This pore size was an important parameter of the bone implant because it played a role in the osteoinductive process. The composite compressive strength test results for freezing 2 hours, 4 hours and 6 hours respectively was 737 KPa, 842 KPa and 707.7 KPa. The results of the cytotoxicity test with MTT showed the percentage of cell viability above 100%. This means that the Hydroxyapatite-collagen composite is non-toxic. So, the sample formed has qualified as a bone implant candidate.

Numerical investigation of the role of osteopontin on the mechanical strength of biological composites

The material components and configurations inside biological materials (e.g. bone and tooth) are quite dissimilar compared to conventional engineering materials. Besides hydroxyapatite minerals and collagen proteins, non-collagenous proteins such as osteopontin are also a very important component in bone. The aim of this paper is to study the role of osteopontin on the mechanical strength of biological composites. The MD simulations were performed to investigate the failure energy of osteopontin in two different directions, i.e. the direction normal to surface (thickness direction) and the direction tangential to surface (interface direction). The FE simulations were then performed to investigate the effects of failure energy in different directions on biological composites. The results show that the failure energy of osteopontin is higher in the interface direction. Significant improvement in the mechanical behaviour of biological composites is also found with the increased failure energy in the interface direction. Contrarily, although lower failure energy of osteopontin is observed in the thickness direction, but it is also found that the mechanical behaviour of biological composites does not greatly affected by the failure energy in the thickness direction. The numerical investigation provides important insights into how the osteopontin affects the mechanical behaviour of biological composites.

Collagen-hydroxyapatite composite substitute and bone marrow nuclear cells on posterolateral spine fusion in sheep.

The effects of a large collagen-hydroxyapatite (COL-HA) substitute with or without isolated bone marrow nuclear cells (BMNC) on spine fusion were evaluated using a two-level posterolateral spinal f...

Effect of pore size in bone regeneration using polydopamine-laced hydroxyapatite collagen calcium silicate scaffolds fabricated by 3D mould printing technology.

The pore size of the scaffold is a critical factor in repairing large bone defect. Here, we investigated the potential of bone regeneration using novel nanocomposite polydopamine-laced hydroxyapatite collagen calcium silicate (HCCS-PDA) scaffolds with two different pore sizes, 250 and 500μm. A total of 12 male Sprague-Dawley rats were implanted with HCCS-PDA scaffold with pore size of either 250 or 500μm into surgically created critical-sized defect (CSD). HCCS-PDA scaffolds were fabricated using mould printing technique. The effect of pore size on mechanical strength of the scaffolds was assessed by compression testing. After seeding with rat mesenchymal stem cells (rMSCs), the scaffolds were implanted, and new bone formation was evaluated using microCT and histomorphometric analysis after 8weeks. MicroCT and histology analysis demonstrated restricted peripheral new bone formation in either dural or periosteal side and limited new bone formation in the 250μm pore scaffold. Conversely, the 500-μm pore scaffold showed more penetration of new bone into the scaffold and greater bone regeneration in the rat CSD. Based on our results, which demonstrated improved new bone formation in 500μm pores scaffold, we can conclude that effective scaffold pore size that induces osteointegration and bone regeneration is around 500μm for HCCS-PDA nanocomposite scaffold.

Bone Marrow Aspirate in Cystic Maxillofacial Bony Defects.

Autogenous or alloplastic bone grafts are routinely applied for reconstruction of cystic bone defects. Addition of mesenchymal bone marrow stem cell in osteoconductive alloplastic bone makes it osteoinductive and osteogenic. The purpose of this study was to evaluate the role of bone marrow aspirate in regenerating new bone with hydroxyapatite collagen scaffold in patients with large cystic maxillofacial defects. This prospective randomized study had random allocation of 15 patients with large cystic maxillofacial bony defects in each of the 2 groups. Group I patients received hydroxyapatite granules and bone marrow aspirate in collagen sponge and group II received hydroxyapatite granules only. Clinical and radiologic assessment showed the time taken in bone healing. In group I, the bone defect volume reduction was statistically significant at 3 and 6 months, the postoperative pain and swelling was less, and there was no tooth mobility at 3 months. The authors concluded that use of hydroxyapatite granules with bone marrow aspirate in collagen sponge in maxillofacial bone defects provided early bone regeneration, and faster wound healing. However, to arrive at a definitive conclusion a long-term study with a larger sample size is required.

Synthesis of Biomimetic Materials from Collagen and Hydroxyapatite

New approach is described to synthesis of biomimetic materials on the basis of hydroxyapatite particles and collagen suspension produced from fish-production wastes. A simultaneous joint in vitro precipitation yields partly mineralized collagen fibrils. The process is similar to the mineralization stage in the case of an in vivo formation of bone tissue. The method for synthesizing a collagen-hydroxyapatite biomimetic composite material can serve as a basis for obtaining materials for the regenerative medicine.

The Inhibition of Radial and Axial Micromovement of Bone Scaffold with Gelfoam® and Titanium Mesh Fixation and Its Effects on Osteointegration.

A major drawback of nanocomposite scaffolds in bone tissue engineering is dimensional shrinkage after the fabrication process. Shrinkage yields gaps between the scaffold and host bone in the defect site and eventually causes failure in osteointegration by micromovement. The present study was conducted using titanium (Ti) mesh and Gelfoam® to prevent radial and axial micromovement, respectively. A critical-sized defect (CSD) was created in the center of the calvarium of Sprague Dawley rats to implant porous polydopamine-laced hydroxyapatite collagen calcium silicate (HCCS-PDA), a novel nanocomposite scaffold. Gelfoam® was applied around the edge of the defect, and then the HCCS-PDA scaffold was inserted in the defect area. Ti mesh was placed between the periosteum and skin right, above the inserted scaffold site. There were two test groups, with a fixture (Gelfoam® and Ti mesh) and without a fixture, each group contained five animals. The rats were sacrificed after three months post-operation. The explanted calvaria underwent micro-CT scanning and a push-out test to quantify osteointegration and mechanical strength between the scaffold and host bone. Histological analysis of undecalcified bone was performed by grinding resin infiltrated calvaria blocks to prepare 10 μm slices. Osteointegration was higher in the group with fixation than without fixation. Movement of the HCCS-PDA scaffold in the gap resulted in diminished osteointegration. With fixation, the movement was inhibited and osteointegration became prominent. Here we present a successful method of preventing axial and radial movement of scaffolds using Gelfoam® and Ti mesh. Applying this fixture, we expect that an HCCS-PDA scaffold can repair CSD more effectively.

Biocompatible chitosan-collagen-hydroxyapatite nanofibers coated with platelet-rich plasma for regenerative engineering of the rotator cuff of the shoulder.

Over the last few decades, extraordinary progress has been accomplished in the field of bone tissue engineering. Containing an incredible number of growth factors required for the process of osteogenesis, platelet-rich plasma (PRP) has gained much interest. However, because of the conflicting results obtained in various investigations, its adequacy remains a riddle. Accordingly, in this paper, we explore the in vitro application of biocompatible chitosan–collagen–hydroxyapatite (CS–COLL–HAP) nanofibers coated with platelet-rich plasma (PRP) (CS–COLL–HAP/PRP) scaffolds for the regenerative engineering of the rotator cuff (RCF) of the shoulder. FTIR spectroscopy, XRD, SEM-EDX and HRTEM were performed to evaluate the characteristics of nanofibers. After confirmation of the physicochemical properties of nanofibers, the osteogenic capability of the scaffold was assessed by measuring the relative calcium content, ALP activity, and gene expression. The results of viability and live/dead assay and cell adhesion test indicated the adequacy of the PRP when coupled with nanofibers in contrast to the other tested groups. In vivo staining affirmed increased collagen association in the PRP with nanofiber scaffolds at 30 days and 60 days. In conclusion, the addition of the PRP into CS–COLL–HAP nanofibers in this examination affected the osteogenic differentiation of osteoblast cells, and therefore, it may have an incredible perspective for bone tissue applications.

Sequential releasing of VEGF and BMP-2 in hydroxyapatite collagen scaffolds for bone tissue engineering: Design and characterization

The property of biomaterials to control the sequential release of growth factors has been widely concerned in the field of bone repair and regeneration. Double-factor sustained-release scaffolds have good biocompatibility and bioactivity. O‑Carboxymethyl chitosan microspheres (O-CMCS) has antimicrobial activity, biodegradability, biocompatibility and film formation. This study developed scaffolds materials with microspheres with a purpose of forming a controlled slow release secondary structure. O-CMCS were used as drug carrier to construct the compound sustained-release system with rhBMP-2 and VEGF double factors release. The O-CMCS were loaded with rhBMP-2 and the hydroxyapatite collagen (HC) scaffolds were loaded with VEGF to prepare the scaffolds. These were double factors composite sustained-release system scaffolds. The biocompatibility of the sustained-release system was evaluated by in vitro and in vivo experiments. HC composite scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction detection (XRD), in vitro sustained release test, in vitro cell culture and in vivo animal experiments. The results showed that rhBMP-2/VEGF in HC composite scaffolds (HCBV) successfully achieved the sequential release of the double factors, which could benefit bone regeneration.

Rapid microwave-assisted synthesis of gold loaded hydroxyapatite collagen nano-bio materials for drug delivery and tissue engineering application

A rapid microwave assisted facile synthetic technique was adopted to load gold nanoparticles (Au) on hydroxyapatite (HAp) surface. HAp nanoparticles were primarily synthesized by wet precipitation technique and further used for gold loading and successive collagen coating for biomedical applications. The microwave-assisted controlled synthesis technique with three heating cycles allows the very fast growing of Au seeds over HAp facets. Different sophisticated analytical techniques and spectroscopic characterization were employed to confirm the structural, chemical, and morphological features. The synthesized different concentration “Au” loaded hetero nanostructures coated with collagen (Au–HAp–Col) optimized for drug (Doxorubicin: DOX) loading and releasing purposes for biomedical applications. The maximum drug-loading efficiency of ~58.22% and a pH responsive releasing of ~53% (at pH 4.5) was obtained for 0.1 wt% Au–HAp–Col nanoparticles. To study the cytotoxic effects from the hetero nanostructures, MG-63 osteoblast-like cells were exposed to different concentration ranges on Au–HAp, Au–HAp–Col, and DOX loaded Au–HAp–Col nanoparticles. The non-toxic and bioactive properties of the synthesized nanoparticle-fabricated scaffold promotes cellular attachment, growth, and proliferation. These results indicated that optimized Au–HAp–Col nanoparticles may be promising drug delivery and scaffold materials for multifunctional biomedical applications.

Hydroxyapatite/collagen coating on PLGA electrospun fibers for osteogenic differentiation of bone marrow mesenchymal stem cells.

The architecture and composition of bone tissue engineering scaffolds play important roles in modulating the growth of bone tissue. Composite fibers composed of poly(lactic-co-glycolic acid) (PLGA) skeleton coated with hydroxyapatite (HA) or hydroxyapatite/collagen (HA/Col) were successfully produced via electrospinning, biomimetic process, and adsorption. The PLGA skeleton fabricated by electrospinning process with a nanofibrous structure (diameter ranging from 200 to 400 nm) showed a morphologic similarity to the extracellular matrix (ECM). SEM, EDX, and XRD analysis confirmed the presence of HA and Col on the composite fibers. Mesenchymal stem cells were used to evaluate the cellular behaviors including cell attachment and spreading, proliferation, and osteogenic differentiation on these fibers (PLGA, PLGA/HA, and PLGA/HA/Col). The results demonstrated that the HA and HA/Col coating improved the interaction between mesenchymal stem cells and the composite fibers reflected by accelerated cell spreading, increased alkaline phosphatase (ALP) activity and enhanced expression of osteogenic-related genes. The HA/Col coating was more effective in improving this interaction compared with HA coating. The PLGA/HA/Col composite fibers may be promising as a candidate scaffold for bone tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2863-2870, 2018.