Research progress in influence of microstructure on performance of triply-periodic minimal surface bone scaffolds / 中国修复重建外科杂志

OBJECTIVE@#To summarize the influence of microstructure on performance of triply-periodic minimal surface (TPMS) bone scaffolds.@*METHODS@#The relevant literature on the microstructure of TPMS bone scaffolds both domestically and internationally in recent years was widely reviewed, and the research progress in the imfluence of microstructure on the performance of bone scaffolds was summarized.@*RESULTS@#The microstructure characteristics of TPMS bone scaffolds, such as pore shape, porosity, pore size, curvature, specific surface area, and tortuosity, exert a profound influence on bone scaffold performance. By finely adjusting the above parameters, it becomes feasible to substantially optimize the structural mechanical characteristics of the scaffold, thereby effectively preempting the occurrence of stress shielding phenomena. Concurrently, the manipulation of these parameters can also optimize the scaffold's biological performance, facilitating cell adhesion, proliferation, and growth, while facilitating the ingrowth and permeation of bone tissue. Ultimately, the ideal bone fusion results will obtain.@*CONCLUSION@#The microstructure significantly and substantially influences the performance of TPMS bone scaffolds. By deeply exploring the characteristics of these microstructure effects on the performance of bone scaffolds, the design of bone scaffolds can be further optimized to better match specific implantation regions.

Research progress on the design of bone scaffolds with different single cell structures / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress of design of bone scaffolds with different single cell structures.@*METHODS@#The related literature on the study of bone scaffolds with different single cell structures at home and abroad in recent years was extensively reviewed, and the research progress was summarized.@*RESULTS@#The single cell structure of bone scaffold can be divided into regular cell structure, irregular cell structure, cell structure designed based on topology optimization theory, and cell structure designed based on triply periodic minimal surface. Different single cell structures have different structural morphology and geometric characteristics, and the selection of single cell structure directly determines the mechanical properties and biological properties of bone scaffold. It is very important to choose a reasonable cell structure for bone scaffold to replace the original bone tissue.@*CONCLUSION@#Bone scaffolds have been widely studied, but there are many kinds of bone scaffolds at present, and the optimization of single cell structure should be considered comprehensively, which is helpful to develop bone scaffolds with excellent performance and provide effective support for bone tissue.

Research status of 3D⁃printed composite PVA bone tissue engineering scaffolds / 口腔疾病防治

@# Three dimensionally printed composite porous bone tissue engineering scaffolds have become a research focus. Composite polyvinyl alcohol (PVA) has good biocompatibilityand degradability, but it cannot be prepared indepen⁃dently because it cannot resist highmechanical resistance. This material shows many advantages, such as good biocom⁃patibility, degradability and mechanical properties, when compounded with other materials with good mechanical proper⁃ties and good biocompatibility. Therefore, 3D printed composite PVA scaffold material can optimize the performance of PVA scaffolds. This article reviews 3D printing bone scaffold technology, polyvinyl alcohol (PVA), and composite PVA scaffolds for in vivo and in vitro bone formation.

Current advances for bone regeneration based on tissue engineering strategies / 医学前沿

Bone tissue engineering (BTE) is a rapidly developing strategy for repairing critical-sized bone defects to address the unmet need for bone augmentation and skeletal repair. Effective therapies for bone regeneration primarily require the coordinated combination of innovative scaffolds, seed cells, and biological factors. However, current techniques in bone tissue engineering have not yet reached valid translation into clinical applications because of several limitations, such as weaker osteogenic differentiation, inadequate vascularization of scaffolds, and inefficient growth factor delivery. Therefore, further standardized protocols and innovative measures are required to overcome these shortcomings and facilitate the clinical application of these techniques to enhance bone regeneration. Given the deficiency of comprehensive studies in the development in BTE, our review systematically introduces the new types of biomimetic and bifunctional scaffolds. We describe the cell sources, biology of seed cells, growth factors, vascular development, and the interactions of relevant molecules. Furthermore, we discuss the challenges and perspectives that may propel the direction of future clinical delivery in bone regeneration.

Clinical application of tissue engineering bone loaded with adipose derived stem cells after flap reconstruction in the treatment of composite tissue defects / 中华显微外科杂志

Objective To investigate the clinical efficacy of using the tissue engineering bone loaded with adipose derived stem cells (ADSCs)and perforator flap in the treatment of composite tissue defects.Methods From April,2013 to June,2015,there were 9 cases of traumatic bone and skin composite tissue defects,including 7 males and 2 females,with an averaged age of 43 years old.The ADSCs were isolated,induced and co-cultured with demineralized bone scaffold.The tissue engineering bone and deep inferior epigastric artery perforator (DIEP) flap were adopted for reconstruction of composite tissue defects.Results All 9 patients were followed up for 12-36 months,averaged of 18 months.The bone growth was obviously for 5 cases with bone defects at the middle and lower part of the tibia.They tolerated full weight bearing walking.One case of middle humeral bone defect demonstrated normal bone tissue growth,and the 2/3 of cross section had been restored.One case of humeral bone defect and 1 case of radial bone defect reached bone union.The remaining 1 with skull defect showed new bone growth,but it had not yet achieved complete bone healing.Conclusion The combination of tissue engineering bone and perforator flap is a minimally invasive,easy accessible and effective method for reconstruction of composite tissue defects.

Comparison of Alginate/Cockle Shell Powder Nanobiocomposite and Alginate/ Calcium Carbonate Bone Scaffolds on Osteoblast Growth / Jurnal Sains Kesihatan Malaysia

Calcium carbonate (CaCO3 ) plays a crucial role in influencing the growth of osteoblast. This study was conducted to compare the performance of alginate/cockle shell powder nanobiocomposite (nCP) bone scaffold developed from naturally occurring CaCO3 with alginate/calcium carbonate (CC) bone scaffold developed using synthetic CaCO3. The study compares the performance of the scaffold in supporting the growth of osteoblast through in vitro evaluations as well as initial biocompatibility observations through in vivo methods. Both scaffolds were developed using the mixture of 40% alginate solution with either 60% of nano cockle shell powder or synthetic CaCO3 to obtain a three dimensional scaffold structure. In vitro evaluation on calcium release and ALP enzyme activity was conducted on both scaffolds seeded with osteoblast on day’s three, five and seven using commercial kits. In vivo observations using histological methods were further conducted by implanting osteoblast seeded scaffold subcutaneously at the dorsum of 8 albino mice for 21 days. Findings from in vitro studies showed a significant increase (p < 0.05) in the release of calcium and ALP enzyme activity in nCP scaffolds on day seven compared to days three and five of CC scaffold. Histological observations using H&E and von Kossa staining showed infiltration and proliferation of osteoblast on both scaffolds as well as early stage bone tissue formation. Formation of new blood vessels within the scaffolds was also observed in nCP scaffold. Both the developed scaffolds were noted to support osteoblast growth and new tissue formation with better potentials displayed by nCP scaffolds comparatively. This study shows that naturally occurring CaCO3 obtained from cockle shells in the form of nano powder has good potentials to be used as a biomaterial for bone tissue engineering applications.

Cytotoxicity and Oxidative Stress Evaluation of Alginate/Cockle Shell Powder Nanobiocomposite Bone Scaffold on Osteoblast / Jurnal Sains Kesihatan Malaysia

Biocompatibility and growth of osteoblast on bone scaffolds play an important role towards their therapeutic application. The presence of oxidative stress generated by bone scaffolds highly influences osteoblast growth and its functional performance. In this study in-vitro interaction of developed Alginate/Cockle Shell powder nanobiocomposite bone scaffold on osteoblast with regards to cytotoxicity and oxidative stress are evaluated. Cytotoxicity studies using MTT assays revealed a significant increase in viability of cultured osteoblast in the presences of the scaffold extracts. The growth of osteoblast on the scaffold were not deterred with the presence of any major oxidative stress factors as determined through oxidative stress profile studies using SOD, GSH and ROS assays. The nanobiocomposite scaffold evaluated in this study shows promising use in regards to facilitating osteoblast proliferation, growth and viability.

Histological reaction of the subcutaneous tissue of rats following implantation of bone morphogenetic protein (rhBMP-2) in inorganic bone scaffold and stimulation using low-power laser light / Reação histológica do tecido subcutâneo de rato após implante de proteína morfogenética óssea(rhBMP-2) em arcabouço de osso inorgânico e estimulado com luz laser de baixa potência

The aim of this study was to assess the histological reaction of the subcutaneous tissue of rats after the implantation of natural inorganic mineral scaffold from a calf femur containing recombinant human bone morphogenetic protein (rhBMP-2) and irradiated with low-power laser light. Material and methods: Sixteen Wistar rats were incised in the torso in a medial-longitudinal orientation, and the subcutaneous tissue of the left and right sides of the incision was pulled apart for implantation of the inorganic bone scaffold containing rhBMP-2. Diode laser light was applied to the right side implant at a dose of 8 J/cm2 for 3 minutes, forming two groups: G1 (control) and G2 (irradiated with laser). Implants and surrounding tissuewere removed from four animals on days 7, 21, 40 and 112 for microscopic study. The histological resultswere assessed by means of grading (0 = absence, 1 = slight presence, 2 = representative and 3 = very representative),considering the following events: formation of osteoid structure, acute inflammation, chronicinflammation, fibrin deposition, neovascularization, foreign body granuloma and fibrosis. Results: The resultsshowed no statistically significant differences in each of the four periods when the two groups werecompared (p>0.05 – Mann-Whitney’s test). Conclusion: The natural inorganic scaffold from a calf femurwith rhBMP-2 was a biocompatible combination. Under these conditions, the inductive capacity of rhBMP-2for cell differentiation was inhibited. A slight hastening of tissue healing was shown in the group that wasirradiated with low-power laser light...

O objetivo deste estudo foi avaliar a reação histológica do tecido subcutâneo de rato após o implante de matriz de osso inorgânico mineral natural de fêmur de vitelo com proteína morfogenética do osso recombinante humana (rhBMP-2) e irradiado com luz laser de baixa potência. Material e métodos: Dezesseis ratos (Wistar) foram incisados no dorso no sentido medio-longitudinal. O tecido subcutâneo do lado direito e esquerdo da incisão foram divulsionados para o implante da matriz de osso inorgânico com rhBMP-2. Na direção do implante do lado direito foi aplicada luz laser, diodo em dose única de 8 J/cm2, por 3 minutos, formando dois grupos: G1 (controle) e G2 (irradiado com laser). Foram removidos implantes com o tecido circundante de quatro animais nos períodos de 7, 21, 40 e 112 dias para estudo microscópico. Os resultados histológicos foram avaliados através de postos (0 = ausência, 1 = discreta presença, 2 = representativo e 3 = muito representativo),considerando os seguintes eventos: formação de estrutura osteoide, inflamação aguda, inflamação crônica, depósito de fibrina, neovascularização, granuloma de corpo estranho e fibrose. Resultados: Os resultados não mostraram diferenças estatísticas significativas nos eventos em cada um dos períodos quando comparados os dois grupos (p>0,05 – teste Mann-Whitney). Conclusão: A matriz de osso inorgânico natural de fêmur de vitelo com rhBMP-2 é um conjunto biocompatível. Nestas condições, a capacidade indutora de diferenciação celular da rhBMP-2 foi inibida. Ficou evidenciado discreto aceleramento na cicatrização tecidual no grupo que foi irradiado com luz laser de baixa potência...

Comparison of the biocompatibility of three kinds of antigen-extracted xenogeneic cancellous bone matrices / 中国组织工程研究

BACKGROUND:The form and structure of antigen-extracted xenogeneic cancel ous bone through series of physical and chemical treatment are similar to human tissue. OBJECTIVE:To detect the biocompatibility of antigen-extracted xenogeneic cancel ous bone matrix prepared by three different ways. METHODS:The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods and hydroxy apatite biological ceramic materials were implanted into the dorsum subcutaneous tissue. Histological observation was done at 4, 8 and 12 weeks after surgery. The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods respectively was used to culture sheep bone marrow mesenchymal stem cells for 7 days. Cel adhesion, growth, proliferation and stroma secretion were observed. RESULTS AND CONCLUSION:At 4 weeks after surgery, a strong inflammatory reaction was detected around materials in four groups. At 12 weeks, the xenogeneic bone materials prepared through physical and physical-chemical combined methods and hydroxy apatite biological ceramic materials internal pore and surrounding tissue inflammation disappeared basical y, with the presence of thimbleful inflammation cells. The material degradation was more than at 8 weeks. The xenogeneic bone materials prepared through chemical methods material internal pore and surrounding tissue inflammation stil existed, suggesting that the xenogeneic bone materials prepared through physical and physical-chemical combined methods exhibited good histocompatibility. A smal amount of orderly osteoblasts existed around hydroxy apatite biological ceramic materials and physical-chemical prepared materials, with a smal amount of bone. These suggested that there was a tendency for ectopic bone formation. The xenogeneic cancel ous bone materials prepared through physical or physical-chemical combined methods have better cytocompatibility. However, scaffold materials prepared through chemical method have poor cytocompatibility and they are not qualified for the safety standards of biological materials.

Histological and radiographic evaluation of the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2) in a scaffold of inorganic bone and after stimulation with low-power laser light.

Objective: The present study histologically and radiologically evaluates the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2) in a natural inorganic bone mineral scaffold from a bull calf femur and irradiation with low-power light laser. Materials and Methods: The right and left hind limbs of 16 rats were shaved and an incision was made in the muscle on the face corresponding to the median portion of the tibia, into which rhBMP-2 in a scaffold of inorganic bone was implanted. Two groups of limbs were formed: control (G1) and laser irradiation (G2). G2 received diode laser light applied in the direction of the implant, at a dose of 8 J/cm2 for three minutes. On the 7th, 21st, 40th and 112th days after implantation, hind limbs of 4 animals were radiographed and their implants removed together with the surrounding tissue for study under the microscope. The histological results were graded as 0=absence, 1=slight presence, 2=representative and 3=very representative, with regard to the following events: formation of osteoid structure, acute inflammation, chronic inflammation, fibrin deposition, neovascularization, foreign-body granuloma and fibrosis. Results: There were no statistically significant differences in these events at each evaluation times, between the two groups (P>0.05; Mann-Whitney test). Nevertheless, it could be concluded that the natural inorganic bone matrix with rhBMP-2, from the femur of a bull calf, is a biocompatible combination. Conclusions: Under these conditions, the inductive capacity of rhBMP-2 for cell differentiation was inhibited. There was a slight acceleration in tissue healing in the group that received irradiation with low-power laser light.