The stimulation of osteogenic differentiation of mesenchymal stem cells and vascular endothelial growth factor secretion of endothelial cells by β-CaSiO3/β-Ca3(PO4)2 scaffolds

Calcium silicate-stimulated adipose-derived stem cells promote angiogenesis and improve skin wound healing

Skin wound healing is a complicated process involving proliferation, inflammation, coagulation, and hemostasis, and scar tissue formation of wound repairing. Adipose-derived stem cells (ADSCs) have presented potential therapeutic effects in the non-healing and chronic wound. Calcium silicate (CS) ceramics have been identified as a new type of bioceramics for tissue construction and regeneration. Here, we aimed to explore the impact of CS on the regulation of ADSCs-mediated wound healing. Significantly, CS was able to dose-dependently enhance the proliferation of ADSCs. CS inhibited terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells in the H₂O₂-treated ADSCs. Similarly, the Bcl-2 expression was elevated while Bax and cleaved caspase-3 expression were repressed by CS in the cells. CS could induce migration and reduce oxidative stress of ADSCs. Moreover, immunofluorescence analysis and Western blot analysis showed that CS could promote CXCR4 expression in ADSCs. Moreover, CS-stimulated ADSCs enhanced migration and angiogenic capacity of HUVEC. Importantly, CS-stimulated ADSCs improved wound healing in full-thickness skin defect mouse model. Thus, we conclude that CS improves ADSCs-attenuated wound healing in vivo and in vitro. Our finding presents novel insight in the scenario that CS regulates ADSCs and wound healing. CS may be applied as potential materials for the treatment of wound healing.

Ceramic Nanofiber Materials for Wound Healing and Bone Regeneration: A Brief Review

Ceramic nanofibers have been shown to be a new horizon of research in the biomedical area, due to their differentiated morphology, nanoroughness, nanotopography, wettability, bioactivity, and chemical functionalization properties. Therefore, considering the impact caused by the use of these nanofibers, and the fact that there are still limited data available in the literature addressing the ceramic nanofiber application in regenerative medicine, this review article aims to gather the state-of-the-art research concerning these materials, for potential use as a biomaterial for wound healing and bone regeneration, and to analyze their characteristics when considering their application.

Effects of Raster Angle and Material Components on Mechanical Properties of Polyether-Ether-Ketone/Calcium Silicate Scaffolds

Polyetheretherketone (PEEK) was widely used in the fabrication of bone substitutes for its excellent chemical resistance, thermal stability and mechanical properties that were similar to those of natural bone tissue. However, the biological inertness restricted the osseointegration with surrounding bone tissue. In this study, calcium silicate (CS) was introduced to improve the bioactivity of PEEK. The PEEK/CS composites scaffolds with CS contents in gradient were fabricated with different raster angles via fused filament fabrication (FFF). With the CS content ranging from 0 to 40% wt, the crystallinity degree (from 16% to 30%) and surface roughness (from 0.13 ± 0.04 to 0.48 ± 0.062 μm) of PEEK/CS scaffolds was enhanced. Mechanical testing showed that the compressive modulus of the PEEK/CS scaffolds could be tuned in the range of 23.3–541.5 MPa. Under the same printing raster angle, the compressive strength reached the maximum with CS content of 20% wt. The deformation process and failure modes could be adjusted by changing the raster angle. Furthermore, the mapping relationships among the modulus, strength, raster angle and CS content were derived, providing guidance for the selection of printing parameters and the control of mechanical properties.

Maxillary Sinus Augmentation With Calcium Phosphate Double-Coated Anorganic Bovine Bone: Comparative Multicenter Randomized Clinical Trial With Histological and Radiographic Evaluation

PURPOSE

The purpose of this study was to evaluate the clinical, histological and radiographic outcomes of the calcium phosphate double-coated anorganic bovine bone (InduCera; Oscotec Inc., Seongnam, Gyeonggi, Republic of Korea) compared with that of anorganic bovine bone (Bio-Oss; Geistlich Biomaterials, Wolhusen, Switzerland) in maxillary sinus augmentation, prospectively.

PATIENTS AND METHODS

Twenty-eight sinuses in 25 patients (3 bilateral) with vertical alveolar bone height from 2 to 5 mm were included in this study. The maxillary sinus was augmented with InduCera or Bio-Oss, followed by a healing period of 6 months. Trephine cores were obtained for histomorphometric evaluation with the implant placement. Cone-beam computed tomography (CBCT) scans were taken at 1 week and 6 months after sinus augmentation.

RESULTS

The graft sites were healed without any notable complications in both groups. In histomorphometric analysis, the area of the newly formed bone was measured as 21.37 ± 8.87% for InduCera and 23.02 ± 5.88% for Bio-Oss, with no significant differences. Radiographically, no statistically significant differences were calculated between the groups in bone height at baseline, the height of bone augmentation, the final alveolar bone height (alveolar bone height + augmented height) after 6 months in panoramic radiograph. There were also no significant differences in the shrinkage rate of the grafted area volume in CBCT.

CONCLUSION

Although calcium phosphate double-coated anorganic bovine bone showed no additional effect compared with anorganic bovine bone from a histological and radiographical point of view, it could be used as the bone graft material in maxillary sinus augmentation.

Amorphous carbon modification on implant surface: a general strategy to enhance osteogenic differentiation for diverse biomaterials via FAK/ERK1/2 signaling pathways

Amorphous carbon coatings enhance osteogenic differentiation via FAK/ERK1/2 signaling pathways.

Core-Shell Biphasic Microspheres with Tunable Density of Shell Micropores Providing Tailorable Bone Regeneration

IMPACT STATEMENT

We have developed the new core-shell bioceramic CSi-Sr4@CaP-px microspheres with tuning porous shell layer so that the biodegradation of both CSi-Sr4 core and CaP shell is readily adjusted synergistically. This is for the first time, to the best of our knowledge, that the bioceramic scaffolds concerning gradient distribution and microstructure-tailoring design is available for tailoring biodegradation and ion release (bioactivity) to optimizing osteogenesis. Furthermore, it is possibly helpful to develop new bioactive scaffold system for time-dependent tailoring bioactivity and microporous structure to significantly enhance bone regeneration and repair applications, especially in some non-load-bearing arbitrary 3D anatomical bone and teeth defects.

Pigment epithelium-derived factor: a key mediator in bone homeostasis and potential for bone regenerative therapy

Objectives

Pigment epithelium-derived factor (PEDF), a multifunctional endogenous glycoprotein, has a very wide range of biological actions, notably in bone homeostasis. The question has been raised regarding the place of PEDF in the treatment of bone disorders and osteosarcoma, and its potential for tumour growth suppression.

Methods

The PubMed database was used to compile this review.

Key findings

Pigment epithelium-derived factor's actions in osteoid tissues include promoting mesenchymal stem cell commitment to osteoblasts, increasing matrix mineralisation, and promoting osteoblast proliferation. It shows potential to improve therapeutic outcomes in treatment of multiple cancer types and regrowth of bone after trauma or resection in animal studies. PEDF may possibly have a reduced adverse effect profile compared with current osteo-regenerative treatments; however, there is currently very limited evidence regarding the safety or efficacy in human models.

Summary

Pigment epithelium-derived factor is very active within the body, particularly in osseous tissue, and its physiological actions give it potential for treatment of both bone disorders and multiple tumour types. Further research is needed to ascertain the adverse effects and safety profile of PEDF as a therapeutic agent.

Endocytic mechanisms and osteoinductive profile of hydroxyapatite nanoparticles in human umbilical cord Wharton's jelly-derived mesenchymal stem cells

Background

As a potentially bioactive material, the widespread application of nanosized hydroxyapatite (nano-HAP) in the field of bone regeneration has increased the risk of human exposure. However, our understanding of the interaction between nano-HAP and stem cells implicated in bone repair remains incomplete.

Methods

Here, we characterized the adhesion and cellular internalization of HAP nanoparticles (HANPs) with different sizes (20 nm np20 and 80 nm np80) and highlighted the involved pathway in their uptake using human umbilical cord Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs). In addition, the effects of HANPs on cell viability, apoptosis response, osteogenic differentiation, and underlying related mechanisms were explored.

Results

It was shown that both types of HANPs readily adhered to the cellular membrane and were transported into the cells compared to micro-sized HAP particles (m-HAP; 12 μm). Interestingly, the endocytic routes of np20 and np80 differed, although they exhibited similar kinetics of adhesion and uptake. Our study revealed involvement of clathrin- and caveolin-mediated endocytosis as well as macropinocytosis in the np20 uptake. However, for np80, clathrin-mediated endocytosis and some as-yet-unidentified important uptake routes play central roles in their internalization. HANPs displayed a higher preference to accumulate in the cytoplasm compared to m-HAP, and HANPs were not detected in the nucleolus. Exposure to np20 for 24 h caused a decrease in cell viability, while cells completely recovered with an exposure time of 72 h. Furthermore, HANPs did not influence apoptosis and necrosis of hWJ-MSCs. Strikingly, HANPs enhanced mRNA levels of osteoblast-related genes and stimulated calcium mineral deposition, and this directly correlated with the activation in c-Jun N-terminal kinases and p38 pathways.

Conclusion

Our data provide additional insight about the interactions of HANPs with MSCs and suggest their application potential in hard tissue regeneration.

Advanced Therapy Medicinal Products: A Guide for Bone Marrow-derived MSC Application in Bone and Cartilage Tissue Engineering

Millions of people worldwide suffer from trauma- or age-related orthopedic diseases such as osteoarthritis, osteoporosis, or cancer. Tissue Engineering (TE) and Regenerative Medicine are multidisciplinary fields focusing on the development of artificial organs, biomimetic engineered tissues, and cells to restore or maintain tissue and organ function. While allogenic and future autologous transplantations are nowadays the gold standards for both cartilage and bone defect repair, they are both subject to important limitations such as availability of healthy tissue, donor site morbidity, and graft rejection. Tissue engineered bone and cartilage products represent a promising and alternative approach with the potential to overcome these limitations. Since the development of Advanced Therapy Medicinal Products (ATMPs) such as TE products requires the knowledge of diverse regulation and an extensive communication with the national/international authorities, the aim of this review is therefore to summarize the state of the art on the clinical applications of human bone marrow-derived stromal cells for cartilage and bone TE. In addition, this review provides an overview of the European legislation to facilitate the development and commercialization of new ATMPs.

Enhancing the Osteogenic Capability of Core-Shell Bilayered Bioceramic Microspheres with Adjustable Biodegradation

This study describes the fabrication and biological evaluation of core-shell bilayered bioceramic microspheres with adjustable compositional distribution via a coaxial bilayer capillary system. Beyond the homogeneous hybrid composites, varying the diameter of capillary nozzles and the composition of the bioceramic slurries makes it easy to create bilayered β-tricalcium phosphate (CaP)/β-calcium silicate (CaSi) microspheres with controllable compositional distribution in the core or shell layer. Primary investigations in vitro revealed that biodegradation could be adjusted by compositional distribution or shell thickness and that poorly soluble CaP located on the shell layer of CaP or CaSi@CaP microspheres was particularly beneficial for mesenchymal stem cell adhesion and growth in the early stage, but the ion release from the CaP@CaSi exhibited a potent stimulating effect on alkaline phosphatase expression of the cells at longer times. When the bilayered microspheres (CaSi@CaP, CaP@CaSi) and the monolayered microspheres (CaP, CaSi) were implanted into the critical-sized femoral bone defect in rabbit models, significant differences in osteogenic capacity over time were measured at 6-18 weeks post implantation. The CaP microspheres showed the lowest biodegradation rate and slow new bone regeneration, whereas the CaSi@CaP showed a fast degradation of the CaSi core through the porous CaP shell so that a significant osteogenic response was observed at 12-18 weeks. The CaP@CaSi microspheres possessed excellent surface bioactivity and osteogenic activity, whereas the CaSi microspheres group exhibited a poor bone augmentation in the later stage due to extreme biodegradation. These findings demonstrated that the bioactive response in such core-shell-structured bioceramic systems could be adjusted by compositional distribution, and this strategy can be used to fabricate a variety of bioceramic microspheres with adjustable biodegradation rates and enhanced biological response for bone regeneration applications in medicine.

Pigment epithelium derived factor upregulates expression of vascular endothelial growth factor by human mesenchymal stem cells: Possible role in PEDF regulated matrix mineralization

Pigment epithelium-derived factor (PEDF) encoded by serpinf1 is a potent antiangiogenic factor found in a wide variety of fetal and adult tissues. Several reports have shown that lack of PEDF leads to osteogenesis imperfecta (OI) type VI whose hallmark is a defect in mineralization that leads to excessive osteoid build up that fails to mineralize. Because PEDF is antiangiogenic factor it would pose serious consequences on bone development and healing of fractures. To understand possible mechanisms by which PEDF plays a role in bone development and regulation of matrix mineralization, we determined the effects of exogenous PEDF on vascular endothelial growth factor (VEGF) expression by human mesenchymal stem cells (hMSCs) and mechanisms of its regulation by PEDF. Human MSCs incubated in normal medium supplemented with exogenous PEDF increased VEGF expression; this increase was also seen when PEDF was added to hMSCs undergoing osteogenic differentiation. MSCs maintained in osteogenic medium increased synthesis of both VEGF and PEDF but both factors were maintained relatively in balance during differentiation. To understand mechanisms by which exogenous PEDF regulated VEGF expression, hMSCs exposed to PEDF activated Erk signaling pathway in MSCs; inhibition of Erk signaling reduced VEGF mRNA expression as well as protein production suggesting that PEDF regulates VEGF expression in MSCs via Erk signaling pathway. In conclusion, PEDF increases VEGF expression by MSCs suggesting that regulation of VEGF by PEDF may be part of the mechanisms by which PEDF regulates osteoblastic mineralization.

Bioactive calcium silicate extracts regulate the morphology and stemness of human embryonic stem cells at the initial stage

We shed light on the impact of CS extracts on hESC's proliferation and differentiation, which is not clearly investigated.

The outstanding mechanical response and bone regeneration capacity of robocast dilute magnesium-doped wollastonite scaffolds in critical size bone defects

Mechanically strong, highly osteogenic dilute magnesium-doped wollastonite robocast scaffolds.

High mechanical strength bioactive wollastonite bioceramics sintered from nanofibers

The high mechanical strength bioactive wollastonite bioceramics were successfully fabricated via pressureless sintering using nanofibers as raw materials.

In vitro degradability, bioactivity and primary cell responses to bone cements containing mesoporous magnesium-calcium silicate and calcium sulfate for bone regeneration

Mesoporous calcium sulfate-based bone cements (m-CSBC) were prepared by introducing mesoporous magnesium-calcium silicate (m-MCS) with specific surface area (410.9 m² g(-1)) and pore volume (0.8 cm³ g(-1)) into calcium sulfate hemihydrate (CSH). The setting time of the m-CSBC was longer with the increase of m-MCS content while compressive strength decreased. The degradation ratio of m-CSBC increased from 48.6 w% to 63.5 w% with an increase of m-MCS content after soaking in Tris-HCl solution for 84 days. Moreover, the m-CSBC containing m-MCS showed the ability to neutralize the acidic degradation products of calcium sulfate and prevent the pH from dropping. The apatite could be induced on m-CSBC surfaces after soaking in SBF for 7 days, indicating good bioactivity. The effects of the m-CSBC on vitamin D3 sustained release behaviours were investigated. It was found that the cumulative release ratio of vitamin D3 from the m-CSBC significantly increased with the increase of m-MCS content after soaking in PBS (pH = 7.4) for 25 days. The m-CSBC markedly improved the cell-positive responses, including the attachment, proliferation and differentiation of MC3T3-E1 cells, suggesting good cytocompatibility. Briefly, m-CSBC with good bioactivity, degradability and cytocompatibility might be an excellent biocement for bone regeneration.

Degradation and silicon excretion of the calcium silicate bioactive ceramics during bone regeneration using rabbit femur defect model

The investigation of the bone regeneration ability, degradation and excretion of the grafts is critical for development and application of the newly developed biomaterials. Herein, the in vivo bone-regeneration, biodegradation and silicon (Si) excretion of the new type calcium silicate (CaSiO3, CS) bioactive ceramics were investigated using rabbit femur defect model, and the results were compared with the traditional β-tricalcium phosphate [β-Ca3(PO4)2, β-TCP] bioceramics. After implantation of the scaffolds in rabbit femur defects for 4, 8 and 12 weeks, the bone regenerative capacity and degradation were evaluated by histomorphometric analysis. While urine and some organs such as kidney, liver, lung and spleen were resected for chemical analysis to determine the excretion of the ionic products from CS implants. The histomorphometric analysis showed that the bioresorption rate of CS was similar to that of β-TCP in femur defect model, while the CS grafts could significantly stimulate bone formation capacity as compared with β-TCP bioceramics (P < 0.05). The chemical analysis results showed that Si concentration in urinary of the CS group was apparently higher than that in control group of β-TCP. However, no significant increase of the Si excretion was found in the organs including kidney, which suggests that the resorbed Si element is harmlessly excreted in soluble form via the urine. The present studies show that the CS ceramics can be used as safe, bioactive and biodegradable materials for hard tissue repair and tissue engineering applications.

The effect of calcium phosphate composite scaffolds on the osteogenic differentiation of rabbit dental pulp stem cells

The objective of this study is to compare the effects of the two calcium phosphate composite scaffolds on the attachment, proliferation, and osteogenic differentiation of rabbit dental pulp stem cells (DPSCs). One nano-hydroxyapatite/collagen/poly (l-lactide) (nHAC/PLA), imitating the composition and the micro-structure characteristics of the natural bone, was made by Beijing Allgens Medical Science & Technology Co., Ltd. (China). The other beta-tricalcium phosphate (β-TCP), being fully interoperability globular pore structure, was provided by Shanghai Bio-lu Biomaterials Co, Ltd. (China). We compared the absorption water rate and the protein adsorption rate of two scaffolds and the characterization of DPSCs cultured on the culture plate and both scaffolds under osteogenic differentiation media (ODM) treatment. The constructs were then implanted subcutaneously into the back of severely combined immunodeficient (SCID) mice for 8 and 12 weeks to compare their bone formation capacity. The results showed that the ODM-treated DPSCs expressed osteocalcin (OCN), bone sialoprotein (BSP), type I collagen (COLI) and osteopontin (OPN) by immunofluorescence staining. Positive alkaline phosphatase (ALP) staining, calcium deposition and calcium nodules were also observed on the ODM-treated DPSCs. The absorption water rate and protein adsorption rate of nHAC/PLA was significantly higher than β-TCP. The initial attachment of DPSCs seeded onto nHAC/PLA was significantly higher than that onto β-TCP; and the proliferation rate of the cells was also significantly higher than that of β-TCP on 1, 3, and 7 days of cell culture. The ALP activity, calcium/phosphorus content and mineral formation of DPSCs + β-TCP were significantly higher than DPSCs + nHAC/LA. When implanted into the back of SCID mice, nHAC/PLA alone had no new bone formation, newly formed mature bone and osteoid were only observed in β-TCP alone, DPSCs + nHAC/PLA and DPSCs + β-TCP, and this three groups displayed increased bone formation over the 12-week period. The percentage of total bone formation area had no difference between DPSCs + β-TCP and DPSCs + nHAC/PLA at each time point, but the percentage of mature bone formation area of DPSCs + β-TCP was significantly higher than that of DPSCs + nHAC/PLA. Our results demonstrated that the DPSCs on nHAC/PLA had a better proliferation, and that the DPSCs on β-TCP had a more mineralization in vitro, much more newly formed mature bones in vivo were presented in DPSCs + β-TCP group. These findings have provided a further knowledge that scaffold architecture has different influence on the attachment, proliferation and differentiation of cells. This study may provide insight into the clinical periodontal bone tissue repair with DPSCs + β-TCP construct.

Preparation, characterization, in vitro bioactivity, and cellular responses to a polyetheretherketone bioactive composite containing nanocalcium silicate for bone repair

In this study, a nanocalcium silicate (n-CS)/polyetheretherketone (PEEK) bioactive composite was prepared using a process of compounding and injection-molding. The mechanical properties, hydrophilicity, and in vitro bioactivity of the composite, as well as the cellular responses of MC3T3-E1 cells (attachment, proliferation, spreading, and differentiation) to the composite, were investigated. The results showed that the mechanical properties and hydrophilicity of the composites were significantly improved by the addition of n-CS to PEEK. In addition, an apatite-layer formed on the composite surface after immersion in simulated body fluid (SBF) for 7 days. In cell culture tests, the results revealed that the n-CS/PEEK composite significantly promoted cell attachment, proliferation, and spreading compared with PEEK or ultrahigh molecular weight polyethylene (UHMWPE). Moreover, cells grown on the composite exhibited higher alkaline phosphatase (ALP) activity, more calcium nodule-formation, and higher expression levels of osteogenic differentiation-related genes than cells grown on PEEK or UHMWPE. These results indicated that the incorporation of n-CS to PEEK could greatly improve the bioactivity and biocompatibility of the composite. Thus, the n-CS/PEEK composite may be a promising bone repair material for use in orthopedic clinics.

Evolution of a mesoporous bioactive glass scaffold implanted in rat femur evaluated by (45)Ca labeling, tracing, and histological analysis

Mesoporous bioactive glass (MBG) as a biodegradable scaffold with a nanostructure has attracted significant attention. However, the in vivo evolution of MBG, which includes in situ degradation, the local effect induced by degradation, and the disposition of degradation products, remains unclear. In this study, we performed in situ labeling and synthesis of an MBG scaffold for the first time using (45)CaCl2. The obtained (45)Ca-MBG scaffolds possessed a mesoporous-macroporous cross-linked structure. These (45)Ca-MBG scaffolds were implanted in critical-sized rat femur defects (3 × 3 mm) for 1 day and for 1, 4, 8, and 12 weeks and analyzed by isotopic quantitative tracing. The results illustrated that the MBG scaffolds gradually degraded over time and persisted at a local level of approximately 9.63% at week 12. This finding suggests that only a very small amount of MBG-released calcium ions may have been transformed into calcium components of the new bone matrix. The research also confirmed that the active ingredients derived from the degradation of MBG scaffolds could actively regulate the mRNA expression levels of osteoblast-related genes in rat bone marrow-derived mesenchymal stem cells (rBMSCs) and promote bone regeneration in vivo. Moreover, through isotopic tracing of the entire body, (45)Ca, which disappeared in situ after implantation, could be detected in the heart, lungs, spleen, kidneys, intestines, and brain via the blood and was mainly accumulated in distal bone tissue, including the radius and cranium. However, (45)Ca radioactivity in the body tissues significantly decreased or disappeared after 12 weeks. Systemic toxicological studies on MBG scaffolds demonstrated the degradation products that spread to major organs did not cause abnormal histopathological changes. The above discoveries comprehensively address crucial issues regarding the application of MBG in vivo, and these findings provide a scientific basis for introducing a material with mesoporous structure into clinical applications.