Papers by Keyword: Bone Regeneration

Abstract: Bone regeneration is a complex physiological process that helps in healing of fractured bone and maintaining skeletal integrity. Chitosan and Hydroxyapatite (HAp) are bio-materials that enhance bone regeneration. The synergistic influence draws the attention of researchers to the use of Chitosan-HAp composite for bone regeneration. However, there is a need to explore more on material properties, fabrication techniques, biological mechanisms and challenges in bone regeneration applications. The biocompatibility, osteoconductivity, and synergistic effects of chitosan and HAp play a vivid role in bone regeneration. This paper explores recent advancements in the development of scaffolds that mimic the extracellular matrix and promote effective bone healing, fabrication techniques such as freeze-drying, 3D printing and nanotechnology, it also explores limitations regarding mechanical properties, scalability, and regulatory hurdles despite the promising attributes of chitosan-HAp composites. The findings show that the use of machine-learning (ML) in forecasting design output and preclinical applications can improve the composite development for effective bone regeneration. Therefore, future research directions should focus on alternative biopolymers, and employ ML techniques to enhance scaffold design and functionality to optimise material properties.

Abstract: Extensive research is currently focused on finding alternative treatment for bone regeneration, due to the complexity and risks associated with existing procedures. One such alternative under investigation is the utilization of biodegradable nanofiber membranes, fabricated using an electrospinning method. In this study, polycaprolactone (PCL) was used as the main matrix to form electrospun membranes at different electrospinning parameters with the incorporation of estradiol to address bone regeneration capability. The effects of estradiol incorporation within the PCL membranes while determining the appropriate electrospinning parameters through morphological, chemical functionalities and wettability analyses were investigated. The inclusion of estradiol into the PCL matrix has reduced the nanofiber diameter and improved the wettability properties of the membranes. The alterations of electrospinning voltage and flow rate also impacted on the reduction of fiber diameter and wettability, which highlights the membrane’s potential for further cell attachment and bone regeneration.

Abstract: Bone graft materials are widely used in orthopedic and maxillofacial surgeries. The controlled resorbability of the graft material is essential for bone regeneration. Hydroxyapatite and biphasic calcium phosphate bone grafts have poor resorption and limited bone conductive effects. Histology analyses of bone biopsy from SCPC grafted human extraction sockets showed complete bone regeneration and graft resorption in absence of osteoclasts and macrophages. The hypothesis of the present study is that bioactive SCPC inhibits osteoclast’s activity due to the presence of resorbable silica phase in the material. Our objective is to analyze the effect of SCPC dissolution products on the resorption activity of osteoclasts. The conditioned medium was prepared by immersion of SCPC resorbable bioactive SCPC porous granules (Shefabone, Inc, USA) in cell culture medium at various ratios at 37°C for 3 days. The concentration of Si ions released from the SCPC granules into cell culture medium was measured using ICP-OES. Osteoclast precursors derived from human bone marrow were seeded on bone slices and cultured in the conditioned medium containing 10% FBS and osteoclast induction factors. Osteoclast differentiation and resorption were evaluated by TRAP staining and measurement of the volume of resorption pits on the bone slices. Mature multinuclear giant TRAP-positive osteoclasts were observed on the bone substrates after 14 days incubation in control medium containing osteoclast induction factors. In conditioned medium, the number of multinuclear TRAP-positive cells was significantly decreased as the concentration of SCPC dissolved silica increased. The dissolution of silica from SCPC into the culture medium correlates well with down regulation of osteoclast differentiation and the rapid bone regeneration in human bone defects.

Abstract: Bone regeneration is complex physiological process, which include the most common form of regeneration - bone fracture healing and new bone formation. Moreover, large bone defects, infections and bone diseases such as osteoporosis and arthritis can impair bone regeneration. Despite intensive research and development of biomaterials for bone tissue engineering, especially for osteoporotic bone healing, the properties of the fabricated biomaterials are still far from those of unique composite structure of natural bone and desired therapeutic effect not achieved. This mini-review will highlight the various cutting-edge injectable inorganic-organic biocomposites as minimally invasive and regenerative therapeutics for bone tissue regeneration. The review will summarize the main strategic tools for the development of injectable biocomposites: natural or synthetic biopolymer-based hydrogels, bioactive inorganic fillers and biologically active components, as well as the fabrication techniques and synthesis methods.

Abstract: Bone displays an amazing capacity for endogenous self-remodeling. However, compromised bone healing and recovering is on the ascent because of population aging, expanding rate of bone injury and the clinical requirement for the advancement of elective choices to autologous bone unions. Current strategies, including biomolecules, cell treatments, biomaterials and diverse combinations of these, are presently created to encourage the vascularization and the engraftment of the grafts, to reproduce at last a bone tissue with similar properties and attributes of the local bone. In this review, we look through the current techniques that are right now created, utilizing biomolecules, cells and biomaterials, to initiate, coordinate and potentiate bone regeneration and healing after damage and further talk about the natural procedures related with this repair.

Abstract: Simvastatin (SIM) is widely used as a cholesterol-lowering drug known to affect bone formation in vivo and its sustainable administration into localized area is of particular interest. We reported previously that sustained SIM release from poly (lactic-co-glycolide) (PLGA) microspheres could maintain relatively low concentration in the bone defect area, resulting in the improved bone regeneration effect. The aim of this study was to determine the release characteristics of SIM from calcium phosphate coated SIM-loaded PLGA Microspheres (CSPMs) dispersed into an alginate hydrogel bead (with different drug release profiles), since we speculated that further sustainable SIM release would be more effective related to stimulate the formulation of BMP-2, resulting in the promoted bone regeneration.

Abstract: Some biomaterials can be used to promote tissue repair process. The biological substitutes (biomaterials such as hydroxyapatite beads) can be used with some advantages and purpose of mimicking responses to on-site repair of the injured bone. The objective of this study was to evaluate the osteogenic potential of the biomaterial composed of hydroxyapatite and alginate in place of the critical defect. bioceramic samples stoichiometric hydroxyapatite was produced by the precipitation method, wet method with ion molar ratio of Ca 10 (PO 4) 6 (OH) 2, in which the Ca / P ratio was equal to 1.67. The reaction conditions were favorable to the composition of a biomaterial with crystalline phase. The synthesis of the biomaterial composed of hydroxyapatite and alginate microspheres (HAAlg5%; 200 ø 425mm) was obtained from two primary solutions with the aim of, in optimal reactive conditions, to form the precipitate. After synthesis the microspheres were implanted into the defect site. The potential effects of using HAAlg5% and the application of vibratory waves in the critical defect repair were unknown and the results described in this study are promising, considering the systemic therapy and at the site of injury. The biomaterial used promoted repair the injured tissue.

Abstract: Sinus floor augmentation (SFA) has become a well-established pre-implantology procedure for alveolar ridge augmentation of the posterior maxilla. Using bioceramic bone substitutes avoids second-site surgery for autograft harvesting. Compared to the bone substitutes which are currently clinically available, there is a significant need for bone substitutes which degrade more rapidly, but still stimulate osteogenesis at the same time. This has led to the development of bioactive, rapidly resorbable calcium alkali orthophosphate (CAOP) materials, which have a greater solubility than tricalcium phosphate. In this study the biodegradability and effect of a silica containing CAOP (Si-CAOP) on osteogenesis was evaluated in human biopsies sampled 6 months after SFA and compared to that of TCP utilizing hard tissue histology, histomorphometry and immunohistochemical analysis of osteogenic marker expression. Both materials facilitated bone formation and matrix mineralization, which were still actively progressing from the sinus floor in an apical direction 6 months after SFA. With the Si-CAOP grafting material however, bone formation, the bone-biomaterial-contact, i.e. bone-bonding, and particle degradation were significantly greater compared to TCP in the apical region of the biopsies, i.e. at the largest distance from the native bone of the sinus floor. This was accompanied by greater expression of Col I, BSP and OC in the newly formed bone tissue in the Si-CAP samples compared to TCP. Six months after implantation Si-CAOP facilitated greater bone formation and biodegradability than the TCP graft material, whose excellent osteoconductive properties have been widely documented. Consequently, Si-CAOP can be regarded as excellent grafting material for SFA in a clinical setting.

Abstract: This is preliminary study in order to investigate the effect of dental pulp stem cells (DPSCs) on bone regeneration in an animal model. New Zealand rabbits were used as animal model. The critical defect was created in femoral bone and transplantation of DPSCs applied into bone defect. A colorimetric assay was used to detect ALP level in rabbit’s serum. Bone tissue regeneration was evaluated by histological analysis. In the 2nd week, the treated rabbit show increasing in the activity of ALP (157,925 μU) compared to control rabbit (155,361 μU). This increasing trend continues significantly in DPSCs rabbit (169.750 μU) compared to control rabbit (160.406) after 4 weeks. Histological evaluation revealed that the amount of bone lamellae and osteocytes were filled the defect area of DPSCs treated rabbit. Conclusions: Transplantation of DPSCs accelerating bone regeneration by raising ALP level and forming new bone tissue.

Abstract: Variety of different bone substitutive materials are synthetized to improve bone healing potentials in pathological bone conditions. Physiologically active molecules within biomaterials, can initiate expression level of biomarkers, regulating bone remodeling. Aim of our study was to analyze bone healing process in bone defects followed by implantation with 5% strontium substituted hydroxyapatite (HAP) /tricalcium phosphate (TCP) 70/30 granules (group A) or HAP/TCP biphasic ceramic granules without strontium substitution (group B), or sham surgery affected bone (group C) in osteoporotic rabbits’ femur. Tissue samples from contralateral intact left leg were used for evaluation of systemic effects after surgery. Changes of bone volume were measured and appearance of OPG, NFkB-105, OC, COL-1, BMP-2/4, MMP-2, TIMP-2, IL-1 and IL-10-positive osteocytes in osteoporotic rabbits’ bone defect were evaluated. No statistical difference between groups of trabecular bone volume was detected. All analyzed markers showed higher appearance of positive osteocytes in groups A and B with comparison to control left leg (p<0.05). Only NFkB105-positive cells showed important difference between sham surgery affected leg and control one (p=0.034). Numerous OPG-positive cells appeared in group A, while moderate number of them was found in groups B and C (p=0.025; p=0.027). Numerous to abundant OC-positive osteocytes were detected in group A, while moderate in group C (p=0.034). Statistical difference of rest biomarkers between groups was not detected. We concluded that implantation of biomaterials in osteoporotic bone improves local bone regenerative properties. However, the notable increase of OPG-containing cells proves the increase of osteoclastogenesis suppression and gives the evidence for renew of bone functionality.