Guided Bone Regeneration Membrane Research Articles

In vitro and in vivo studies of a biodegradable Zn-4Ag-0.1Sc alloy with high strength-elongation product, cytocompatibility, osteogenic differentiation, and anti-infection properties for guided bone-regeneration membrane applications

Zinc-silver (Zn-Ag) alloys are generally promising guided bone-regeneration membrane (GBRM) materials due to their moderate degradability, osteogenic differentiation, and antibacterial properties. However, Zn-Ag alloys often display microstructural inhomogeneity and mechanical instability due to the formation of coarse Ag-rich second phases. In this study, Zn-4Ag and Zn-4Ag-0.1Sc (denoted ZA and ZAS, respectively) were comparatively investigated, and the ZAS exhibited a suitable degradation rate, high strength-elongation product, cytocompatibility, antibacterial capacity, and in vitro and in vivo osteogenic properties, making it highly appropriate for GBRM applications. Among all the as-cast and hot-rolled (HR) samples, the HR ZAS had the highest ultimate tensile strength of ∼260.5 MPa, tensile yield strength of ∼202.0 MPa, and elongation of ∼72.7%. The HR ZAS also exhibited a higher degradation rate of ∼36.5 µm/a in Hanks’ solution than those of the HR ZA, while its diluted extract was more cytocompatible and capable of osteogenic differentiation toward both MG-63 and MC3T3-E1 cells. The HR ZAS showed an exceptionally effective antibacterial ability against S. aureus in both in vitro antibacterial testing and in vivo subcutaneous infection models. Further, the HR ZAS demonstrated better osteogenic and histocompatibility properties than those of pure Zn in a rat skull defect model.

Self-composite silk fibroin membranes for guided bone regeneration: 1 material 3 architectures with intrinsic integrity

Silk fibroin (SF) takes attention in tissue engineering due to unique features, e.g., excellent biocompatibility/biodegradability with superior mechanical/thermal properties despite its lightweight. Guided bone regeneration (GBR) seeks bilayered GBR membranes to govern bone regeneration, although constituent parts of such membranes may undergo delamination once different biomaterials are combined. Herein, 3-component bilayered SF membranes were prepared for the first time utilizing the same polymer in different forms by eliminating the delamination risk of layers for GBR applications. One side consisted of a non-porous SF film serving as a barrier against penetration of non-osteogenic tissue whereas the other side was porous/fibrous composed of SF sponge and SF fibers for bone regeneration. Proper integration between these layers was confirmed via scanning electron microscopy (SEM). Composites reinforced with high fiber percent (30%) had remarkably enhanced compressive strength and elastic moduli, which were further improved by increasing polymer concentration from 4% to 8%. Non-porous morphology of the barrier side was preserved during 28 days of degradation while pore sizes enlarged on the other surface, which would be beneficial for cell migration into the regenerative side. Saos-2 cells seeded on composites with high fiber percent proliferated more within 14 days; however, alkaline phosphatase (ALP) activity on low-fiber-percent counterparts was elevated more. Osteogenic marker gene expressions were significantly higher than control on day 14. All self-composites were eminent candidates to promote bone regeneration with tailor-made capacity for further improvements. Taken together, 1-material 3-architecture SF fabricated by a green and practical technique holds promise for GBR applications.

A Janus, robust, biodegradable bacterial cellulose/Ti3C2Tx MXene bilayer membranes for guided bone regeneration

Guided bone regeneration (GBR) stands as an essential modality for craniomaxillofacial bone defect repair, yet challenges like mechanical weakness, inappropriate degradability, limited bioactivity, and intricate manufacturing of GBR membranes hindered the clinical efficacy. Herein, we developed a Janus bacterial cellulose(BC)/MXene membrane through a facile vacuum filtration and etching strategy. This Janus membrane displayed an asymmetric bilayer structure with interfacial compatibility, where the dense layer impeded cell invasion and the porous layer maintained stable space for osteogenesis. Incorporating BC with Ti3C2Tx MXene significantly enhanced the mechanical robustness and flexibility of the material, enabling clinical operability and lasting GBR membrane supports. It also contributed to a suitable biodegradation rate, which aligned with the long-term bone repair period. After demonstrating the desirable biocompatibility, barrier role, and osteogenic capability in vitro, the membrane's regenerative potential was also confirmed in a rat cranial defect model. The excellent bone repair performance could be attributed to the osteogenic capability of MXene nanosheets, the morphological cues of the porous layer, as well as the long-lasting, stable regeneration space provided by the GBR membrane. Thus, our work presented a facile, robust, long-lasting, and biodegradable BC/MXene GBR membrane, offering a practical solution to craniomaxillofacial bone defect repair.

The immobilization of a cyclo-trimer of acetonitrile onto poly (lactic acid) (PLA) surface: Improvement of attachment and differentiation of osteoblast-like cells

Poly lactic acid (PLA) has been commercialized as guided bone regeneration membranes. However, PLA membranes are associated with their inherent shortcomings such as insufficient osteoinductive ability. Herein, a cyclo-trimer of acetonitrile (CTA) was covalently immobilized onto PLA films, which would combine the bioactive functions of CTA and good degradability of PLA. The immobilization of CTA enhanced the initial attachment, cell viability, and osteogenic differentiation of osteoblast-like cells. The BMP-SMAD signaling pathway may be involved in the enhancement of osteoinductive capacity of CTA immobilized PLA films. Overall, PLA-CTA films shows a potential for guided bone regeneration.

Shear Flow-Assembled Janus Membrane with Bifunctional Osteogenic and Antibacterial Effects for Guided Bone Regeneration.

Guided bone regeneration (GBR) membranes that reside at the interface between the bone and soft tissues for bone repair attract increasing attention, but currently developed GBR membranes suffer from relatively poor osteogenic and antibacterial effects as well as limited mechanical property and biodegradability. We present here the design and fabrication of a bifunctional Janus GBR membrane based on a shear flow-driven layer by a layer self-assembly approach. The Janus GBR membrane comprises a calcium phosphate-collagen/polyethylene glycol (CaP@COL/PEG) layer and a chitosan/poly(acrylic acid) (CHI/PAA) layer on different sides of a collagen membrane to form a sandwich structure. The membrane exhibits good mechanical stability and tailored biodegradability. It is found that the CaP@COL/PEG layer and CHI/PAA layer contribute to the osteogenic differentiation and antibacterial function, respectively. In comparison with the control group, the Janus GBR membrane displays a 2.52-time and 1.84-time enhancement in respective volume and density of newly generated bone. The greatly improved bone repair ability of the Janus GBR membrane is further confirmed through histological analysis, and it has great potential for practical applications in bone tissue engineering.

Osteoinductive micro-nano guided bone regeneration membrane for in situ bone defect repair

BackgroundBiomaterials used in bone tissue engineering must fulfill the requirements of osteoconduction, osteoinduction, and osseointegration. However, biomaterials with good osteoconductive properties face several challenges, including inadequate vascularization, limited osteoinduction and barrier ability, as well as the potential to trigger immune and inflammatory responses. Therefore, there is an urgent need to develop guided bone regeneration membranes as a crucial component of tissue engineering strategies for repairing bone defects.MethodsThe mZIF-8/PLA membrane was prepared using electrospinning technology and simulated body fluid external mineralization method. Its ability to induce biomimetic mineralization was evaluated through TEM, EDS, XRD, FT-IR, zeta potential, and wettability techniques. The biocompatibility, osteoinduction properties, and osteo-immunomodulatory effects of the mZIF-8/PLA membrane were comprehensively evaluated by examining cell behaviors of surface-seeded BMSCs and macrophages, as well as the regulation of cellular genes and protein levels using PCR and WB. In vivo, the mZIF-8/PLA membrane’s potential to promote bone regeneration and angiogenesis was assessed through Micro-CT and immunohistochemical staining.ResultsThe mineralized deposition enhances hydrophilicity and cell compatibility of mZIF-8/PLA membrane. mZIF-8/PLA membrane promotes up-regulation of osteogenesis and angiogenesis related factors in BMSCs. Moreover, it induces the polarization of macrophages towards the M2 phenotype and modulates the local immune microenvironment. After 4-weeks of implantation, the mZIF-8/PLA membrane successfully bridges critical bone defects and almost completely repairs the defect area after 12-weeks, while significantly improving the strength and vascularization of new bone.ConclusionsThe mZIF-8/PLA membrane with dual osteoconductive and immunomodulatory abilities could pave new research paths for bone tissue engineering.

Engineering a microparticle-loaded rough membrane for guided bone regeneration modulating osteoblast response without inducing inflammation

Guided bone regeneration (GBR) is a widely used procedure that prevents the fast in-growth of soft tissues into bone defect. Among the different types of membranes, the use of collagen membranes is the gold standard. However, these membranes are implanted in tissue location where a severe acute inflammation will occur and can be negatively affected. The aim of this study was to develop a collagen-based membrane for GBR that incorporated alginate-hydroxyapatite microparticles. Membranes were manufactured using collagen type I and gelatin and alginate-hydroxyapatite microparticles. Membranes were assessed in terms of topography by scanning electron microscopy and confocal microscopy; stability by swelling after an overnight incubation in saline and enzymatic degradation against collagenase and mechanical properties by tensile tests. Furthermore, the biological response was assessed with SaOs-2 cells and THP-1 macrophages to determine alkaline phosphatase activity and inflammatory cytokine release. Our results showed that the incorporation of different percentages of these microparticles could induce changes in the surface topography. When the biological response was analyzed, either membranes were not cytotoxic to THP-1 macrophages or to SaOs-2 cells and they did not induce the release of pro-inflammatory cytokines. However, the different surface topographies did not induce changes in the macrophage morphology and the release of pro- and anti-inflammatory cytokines, suggesting that the effect of surface roughness on macrophage behavior could be dependent on other factors such as substrate stiffness and composition. Collagen-gelatin membranes with embedded alginate-hydroxyapatite microparticles increased ALP activity, suggesting a positive effect of them on bone regeneration, remaining unaffected the release of pro- and anti-inflammatory cytokines.

Macrophages in guided bone regeneration: potential roles and future directions.

Guided bone regeneration (GBR) is one of the most widely used and thoroughly documented alveolar bone augmentation surgeries. However, implanting GBR membranes inevitably triggers an immune response, which can lead to inflammation and failure of bone augmentation. It has been shown that GBR membranes may significantly improve in vivo outcomes as potent immunomodulators, rather than solely serving as traditional barriers. Macrophages play crucial roles in immune responses and participate in the entire process of bone injury repair. The significant diversity and high plasticity of macrophages complicate our understanding of the immunomodulatory mechanisms underlying GBR. This review provides a comprehensive summary of recent findings on the potential role of macrophages in GBR for bone defects in situ. Specifically, macrophages can promote osteogenesis or fibrous tissue formation in bone defects and degradation or fibrous encapsulation of membranes. Moreover, GBR membranes can influence the recruitment and polarization of macrophages. Therefore, immunomodulating GBR membranes are primarily developed by improving macrophage recruitment and aggregation as well as regulating macrophage polarization. However, certain challenges remain to be addressed in the future. For example, developing more rational and sophisticated sequential delivery systems for macrophage activation reagents; addressing the interference of bone graft materials and dental implants; and understanding the correlations among membrane degradation, macrophage responses, and bone regeneration.

Development, Characterisation and Biocompatibility Analysis of a Collagen-Gelatin-Hydroxyapatite Scaffold for Guided Bone Regeneration

Guided Bone Regeneration (GBR) is the choice of treatment for improving the horizontal and vertical bone volume through bone grafting. GBR membranes work on the principle of preventing epithelial migration into the defect space while maintaining the space for cell migration and differentiation at the defect site. Hydroxyapatite has been commonly used as a bone graft for infrabony defects. The study was conducted at the Department of Biomaterials at Saveetha Dental College. GBR membrane was prepared and its material characterization was done using Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) analysis, Fourier Transform Infrared Radiation (FTIR), and Confocal Analysis. The developed GBR membrane revealed SEM properties conducive to cell attachment. EDX and FTIR analysis showed the successful development of the collagen-gelatin-hydroxyapatite membrane. Cell culture and confocal analysis revealed excellent biocompatibility with a homogenous layer of viable cells. The developed composite GBR membrane is a biogenic membrane with relevant biomineralization potential that should be applied for GBR applications.

Unveiling the consequences of early human saliva contamination on membranes for guided bone regeneration.

GBR membranes have various surface properties designed to elicit positive responses in regenerative clinical procedures; dental clinicians attempt to employ techniques to prevent the direct interaction of contaminated oral fluids with these biomaterials. However, saliva is uninterruptedly exhibited in oral surgical procedures applying GBR membranes, suggesting a persistent interaction with biomaterials and the surrounding oral tissues. This fundamental study aimed to investigate potential alterations in the physical, chemical, and key biological properties of membranes for guided bone regeneration (GBR) caused by isolated early interaction with human saliva. A reproducible step-by-step protocol for collecting and interacting human saliva with membranes was developed. Subsequently, membranes were evaluated for their physicochemical properties, protein quantification, DNA, and 16S rRNA levels viability of two different cell lines at 1 and 7 days, and ALP activity. Non-interacted membranes and pure saliva of donors were applied as controls. Qualitative morphological alterations were noticed; DNA extraction and 16S quantification revealed significantly higher values. Furthermore, the viability of HGF-1 and MC3T3-E1 cells was significantly (p < .05) reduced following saliva interaction with biodegradable membranes. Saliva contamination did not prejudice PTFE membranes significantly in any biological assay. These outcomes demonstrated a susceptible response of biodegradable membranes to isolated early human saliva interaction, suggesting impairment of structural morphology, reduced viability to HGF-1 and MC3T3-E1, and higher absorption/adherence of DNA/16S rRNA. As a result, clinical oral procedures may need corresponding refinements.

A Periosteum-Bioinspired Electrospun Janus Membrane with Antibacterial and Osteogenic Dual Function.

For a guided bone regeneration membrane, it is critical to possess osteogenic capability while inhibiting infection caused by bacteria. Inspired by the bilayer structure of the native periosteum, an electrospun Janus membrane with osteogenic and antibacterial dual-function is fabricated for guided bone regeneration. Hydrophilic moxifloxacin (MXF) and hydrophobic icariin (ICA) are loaded in the nanofibers made of a mixture of polycaprolactone and gelatin at the top and bottom layers, respectively, leading to the opposing hydrophilic/hydrophobic properties of the bilayer Janus membranes. The as-obtained Janus membrane exhibits excellent physical properties (tensile strength > 6.0MPa) and robust biocompatibility, indicating the immense potential as a suitable replacement for the native periosteum. The membrane has a superior surface morphology and outstanding degradation performance in vitro. Besides, the rapid release of MXF and the slow release of ICA can meet the different needs of drug release rates. Only ≈30% ICA is released from the as-obtained Janus membrane after 21 d while almost 80% MXF is released. Mimicking the bilayer structure of the native periosteum, the electrospun Janus membrane containing ICA and MXF exhibits excellent comprehensive properties, which provides a promising strategy for preparing multifunctional scaffolds for tissue engineering.

Fabrication and characterization of a multi-functional GBR membrane of gelatin-chitosan for osteogenesis and angiogenesis

Guided bone regeneration (GBR) membranes are widely used to treat bone defects. In this study, sequential electrospinning and electrospraying techniques were used to prepare a dual-layer GBR membrane composed of gelatin (Gel) and chitosan (CS) containing simvastatin (Sim)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres (Sim@PLGA/Gel-CS). As a GBR membrane, Sim@PLGA/Gel-CS could act as a barrier to prevent soft tissue from occupying regions of bone tissue. Furthermore, compared with traditional GBR membranes, Sim@PLGA/Gel-CS played an active role on stimulating osteogenesis and angiogenesis. Determination of the physical, chemical, and biological properties of Sim@PLGA/Gel-CS membranes revealed uniform sizes of the nanofibers and microspheres and appropriate morphologies. Fourier-transform infrared spectroscopy was used to characterize the interactions between Sim@PLGA/Gel-CS molecules and the increase in the number of amide groups in crosslinked membranes. The thermal stability and tensile strength of the membranes increased after N-(3-dimethylaminopropyl)-N9- ethylcarbodiimide/N-hydroxysuccinimide crosslinking. The increased fiber density of the barrier layer decreased fibroblast migration compared with that in the osteogenic layer. Osteogenic function was indicated by the increased alkaline phosphatase activity, calcium deposition, and neovascularization. In conclusion, the multifunctional effects of Sim@PLGA/Gel-CS on the barrier and bone microenvironment were achieved via its dual-layer structure and simvastatin coating. Sim@PLGA/Gel-CS has potential applications in bone tissue regeneration.

Strontium-zinc-based phosphate coatings fabricated in situ on the zinc-pretreated magnesium alloy for degradation control and cytocompatibility enhancement

Owing to the good mechanical support, degradability, and biocompatibility, magnesium (Mg) alloys have large potential in medical applications such as guided bone regeneration membranes. However, the rapid degradation of Mg alloys under physiological conditions hinders many clinical applications. Herein, strontium-zinc-based phosphate (SZP) coatings are fabricated in situ on the zinc (Zn)-electrodeposited WE43 Mg alloy for corrosion protection, degradation control, and cytocompatibility enhancement. The Zn coating acts as a protective cathode for the Mg alloy substrate and provides a stable environment to foster the growth of the SZP coating in comparison with direct deposition onto the Mg alloy surface. The virtues are verified by the smaller corrosion current density, corrosion of the Zn coating instead of the Mg alloy substrate after soaking in artificial saliva, as well as good adhesion provided by the Zn-incorporated transition layer of SrZn2(PO4)2 between the Zn coating and SZP coating. The dense and inert SZP coating mitigates degradation as shown by a decrease in the corrosion current density of 44 times to 0.21 uA cm−2 in the simulated oral environment with artificial saliva. Furthermore, the coating resistance and charge transfer resistance increase by more than one order of magnitude compared to the Zn-treated Mg alloy, and there is no obvious degradation after immersion for 7 days. The Zn coating shows adverse effects on the attachment, spreading, and proliferation of MC3T33-E1 pre-osteoblasts, but the SZP coating providing a higher level larger than 100% of the cell viability after incubation with its extract for 3 days is more compatible with cells because of the retarded dissolution and bio-friendly chemical compositions of SrHPO4 and SrZn2(PO4)2. The hybrid coating has excellent prospects in biomedical products such as biodegradable Mg-based guided bone regeneration membranes.

Lysophosphatidic Acid/Polydopamine-Modified nHA Composite Scaffolds for Enhanced Osteogenesis via Upregulating the Wnt/Beta-Catenin Pathway.

Guided bone regeneration (GBR) technology has been widely used for the regeneration of periodontal bone defects. However, the limited mechanical properties and bone regeneration potential of the currently available GBR membranes often limit their repair effectiveness. In this paper, serum-derived growth factor lysophosphatidic acid (LPA) nanoparticles and dopamine-decorative nanohydroxyapatite (pDA/nHA) particles were double-loaded into polylactic-glycolic acid/polycaprolactone (PLGA/PCL) scaffolds as an organic/inorganic biphase delivery system, namely, PP-pDA/nHA-LPA scaffolds. Physicochemical properties and osteogenic ability in vitro and in vivo were performed. Scanning electron microscopy and mechanical tests showed that the PP-pDA/nHA-LPA scaffolds had a 3D bionic scaffold structure with improved mechanical properties. In vitro cell experiments demonstrated that the PP-pDA/nHA-LPA scaffolds could significantly enhance the attachment, proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells. In vivo, the PP-pDA/nHA-LPA scaffolds exhibited great cytocompatibility and cell recruitment ability in 2- and 4-week subcutaneous implantation experiments and significantly promoted bone regeneration in the periodontal defect scaffold implantation experiment. Moreover, LPA-loaded scaffolds were confirmed to enhance osteogenic activities by upregulating the expression of β-catenin and further activating the Wnt/β-catenin pathway. These results demonstrate that the biphase PP-pDA/nHA-LPA delivery system is a promising material for the GBR.

Bredigite bioceramic-based barrier membrane promotes guided bone regeneration by orchestrating an immuno-modulatory and osteogenic microenvironment

Barrier membranes play an important role in guided bone regeneration (GBR) and have been primarily considered as physical barriers. Due to their inherent “foreign body” properties, barrier membranes introduced during GBR procedures unavoidably modify the local immune microenvironment, with consequent impacts on osteogenesis. In bone tissue engineering applications, inorganic bioceramics have been shown to possess the abilities to modulate the local immune response and promote the differentiation of stem cells along osteogenic lineages. Moreover, these bioceramics can be easily incorporated into scaffold membranes, thus demonstrating significant potential as a barrier membrane material for GBR. Herein, an inorganic bredigite (BRT, Ca7MgSi4O16) bioceramic-containing scaffold was fabricated and characterized, and its effects on the immune response and osteogenesis during GBR were investigated. The results indicated that the BRT-containing scaffolds promoted the migration and osteogenic differentiation of bone marrow-derived stem cells (BMSCs). Single-cell RNA sequencing analysis indicated a unique microenvironment and subpopulation of BMSCs cultured on the BRT scaffolds, which exhibited increased osteo/chondrogenic and angiogenic differentiation potential. Furthermore, the BRT-containing scaffolds induced macrophage polarization into the pro-regenerative M2 phenotype, which subsequently promoted the migration and osteogenic differentiation of BMSCs. Additionally, in an in vivo rat model, the BRT-containing membrane was confirmed to enhance the immune microenvironment and support bone regeneration in a cranial critical-size defect. Collectively, these findings indicate that the BRT-containing scaffold membrane possesses dual immunomodulatory and osteogenic properties, offering a potentially beneficial GBR membrane for clinical application.

Silk fibroin/methacrylated gelatine/hydroxyapatite biomimetic nanofibrous membranes for guided bone regeneration

By mimicking in vivo bionic microenvironment and promoting osteogenic differentiation, the hybrid organic-inorganic nanofibrous membranes provide promising potential for guided bone regeneration (GBR) in the treatment of clinical bone defects. To develop a degradable and osteogenic membrane for GBR by combining the natural biomacromolecule silk fibroin (SF) and gelatine with the bioactive nano hydroxyapatite (nHA), the anhydride-modified gelatine-nano hydroxyapatite (GelMA-nHA) composites were synthesized in situ and introduced into silk fibroin to prepare nanofibrous membranes with different ratios using electrospinning and photocrosslinking. The nanofibrous membranes, particularly those with a mass ratio of 7:2:1, were found to exhibit satisfactory elongation at break up to 110 %, maintain the nanofibrous structure for up to 28 days, and rapidly form bone-like apatite within 3 days, thus offering advantages when it comes to guided bone regeneration. In vitro cell results showed that the SF/GelMA/nHA membranes had excellent biocompatibility and enhanced osteogenic differentiation of hBMSCs. In vivo studies revealed that the hybrid composite membranes can improve bone regeneration of critical-sized calvarial defects in rat model. Therefore, the novel hybrid nanofibrous membrane is proposed to be a alternative candidate for creating a bionic microenvironment that promotes bone regeneration, indicating their potential application to bone injury treatment.

Janus Membrane with Intrafibrillarly Strontium-Apatite-Mineralized Collagen for Guided Bone Regeneration.

Commercial collagen membranes face difficulty in guided bone regeneration (GBR) due to the absence of hierarchical structural design, effective interface management, and diverse bioactivity. Herein, a Janus membrane called SrJM is developed that consists of a porous collagen face to enhance osteogenic function and a dense face to maintain barrier function. Specifically, biomimetic intrafibrillar mineralization of collagen with strontium apatite is realized by liquid precursors of amorphous strontium phosphate. Polycaprolactone methacryloyl is further integrated on one side of the collagen as a dense face, which endows SrJM with mechanical support and a prolonged lifespan. In vitro experiments demonstrate that the dense face of SrJM acts as a strong barrier against fibroblasts, while the porous face significantly promotes cell adhesion and osteogenic differentiation through activation of calcium-sensitive receptor/integrin/Wnt signaling pathways. Meanwhile, SrJM effectively enhances osteogenesis and angiogenesis by recruiting stem cells and modulating osteoimmune response, thus creating an ideal microenvironment for bone regeneration. In vivo studies verify that the bone defect region guided by SrJM is completely repaired by newly formed vascularized bone. Overall, the outstanding performance of SrJM supports its ongoing development as a multifunctional GBR membrane, and this study provides a versatile strategy of fabricating collagen-based biomaterials for hard tissue regeneration.

A 3D printed magnesium ammonium phosphate/polycaprolactone composite membrane for Guided bone regeneration

Guided bone regeneration (GBR) is a widely utilized technique for alveolar bone augmentation and the GBR membrane plays a crucial role in this procedure. However, developing a membrane that possesses both mechanical property and biodegradability still remains a challenge. In this study, MgNH4PO4·6H2O (MNP) and polycaprolactone (PCL) were utilized to prepare a novel MNP-PCL composite GBR membrane via 3D printing method, and five different radios of MNP were included (5, 10, 15, 20, 25 wt%). All samples were well prepared into 25 mm × 25 mm square membranes with a thickness of about 0.8 mm. The membranes exhibited promising interconnected network structure with great distribution uniformity, mechanical properties, and biodegradability. Additionally, the membranes also possessed the capacities of sustained magnesium ions release (4 weeks at least) and weakly alkaline environment maintainance (pH 8.0–––8.5), which might be beneficial for promoting bone formation, this hypothesis was then confirmed by in vitro and in vivo studies that the adhesion, proliferation, osteogenic differentiation of MC3T3-E1 and new bone formation were signicantly enhanced on 10 % and 15 % MNP-PCL surfaces. In summary, the MNP-PCL membrane may providing a new approach for the development of GBR membranes in the future.

Resorbable bilayer membrane made of L-lactide-ε-caprolactone in guided bone regeneration: an in vivo experimental study

PurposeGuided bone regeneration (GBR) is an accepted method in dental practice that can successfully increase the bone volume of the host at sites chosen for implant placement; however, existing GBR membranes exhibit rapid absorption and lack of adequate space maintenance capabilities. We aimed to compare the effectiveness of a newly developed resorbable bilayer membrane composed of poly (l-lactic acid) and poly (-caprolactone) (PLACL) with that of a collagen membrane in a rat GBR model.MethodsThe rat calvaria was used as an experimental model, in which a plastic cylinder was placed. We operated on 40 male Fisher rats and subsequently performed micro-computed tomography and histomorphometric analyses to assess bone regeneration.ResultsSignificant bone regeneration was observed, which was and similar across all the experimental groups. However, after 24 weeks, the PLACL membrane demonstrated significant resilience, and sporadic partial degradation. This extended preservation of the barrier effect has great potential to facilitate optimal bone regeneration.ConclusionsThe PLACL membrane is a promising alternative to GBR. By providing a durable barrier and supporting bone regeneration over an extended period, this resorbable bilayer membrane could address the limitations of the current membranes. Nevertheless, further studies and clinical trials are warranted to validate the efficacy and safety of The PLACL membrane in humans.

PVTF Nanoparticles/PLA Electroactive Degradable Membrane for Bone Tissue Regeneration

Electroactive biomaterials can influence the microenvironment between cells and a material’s surface by controlling surface electrical signals, thereby affecting cellular physiological activities. As the most commonly used ferroelectric polymer, Poly(vinylidene fluoride-trifluoroethylene) (PVTF) has attracted widespread attention due to its good stability, biocompatibility and mechanical properties. However, it has limitations such as non-degradability. In this study, PVTF nanoparticles (PVTF NPs), prepared using a phase separation method, were compounded with polylactide (PLA) to prepare PVTF NPs/PLA composite membrane (PN/PLA), which simultaneously achieved electroactivity and degradability. PVTF NPs containing ferroelectric β phase were evenly distributed on the PLA substrate, forming negative potential spots through corona polarization. The PLA substrate gradually degraded in a simulated body fluid environment. The negative surface potential provided by PVTF NPs in PN/PLA enhanced the adhesion, proliferation, and early-stage osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The electrical bioactivity and degradability could be joined together in this study, which is promising for tissue regeneration biomaterials, such as guided bone regeneration membrane.