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Introduction: Bone defects remain a thorny challenge that clinicians have to face. At present, scaffolds prepared by 3D printing are increasingly used in the field of bone tissue repair. Polylactic acid (PLA) has good thermoplasticity, processability, biocompatibility, and biodegradability, but the PLA is brittle and has poor osteogenic performance. Beta-tricalcium phosphate (β-TCP) has good mechanical properties and osteogenic induction properties, which can make up for the drawbacks of PLA.Methods: In this study, photocurable biodegradable polylactic acid (bio-PLA) was utilized as the raw material to prepare PLA/β-TCP slurries with varying β-TCP contents (β-TCP dosage at 0%, 10%, 20%, 30%, 35% of the PLA dosage, respectively). The PLA/β-TCP scaffolds were fabricated using liquid crystal display (LCD) light-curing 3D printing technology. The characterization of the scaffolds was assessed, and the biological activity of the scaffold with the optimal compressive strength was evaluated. The biocompatibility of the scaffold was assessed through CCK-8 assays, hemocompatibility assay and live-dead staining experiments. The osteogenic differentiation capacity of the scaffold on MC3T3-E1 cells was evaluated through alizarin red staining, alkaline phosphatase (ALP) detection, immunofluorescence experiments, and RT-qPCR assays.Results: The prepared scaffold possesses a three-dimensional network structure, and with an increase in the quantity of β-TCP, more β-TCP particles adhere to the scaffold surface. The compressive strength of PLA/β-TCP scaffolds exhibits a trend of initial increase followed by decrease with an increasing amount of β-TCP, reaching a maximum value of 52.1 MPa at a 10% β-TCP content. Degradation rate curve results indicate that with the passage of time, the degradation rate of the scaffold gradually increases, and the pH of the scaffold during degradation shows an alkaline tendency. Additionally, Live/dead staining and blood compatibility experiments suggest that the prepared PLA/β-TCP scaffold demonstrates excellent biocompatibility. CCK-8 experiments indicate that the PLA/β-TCP group promotes cell proliferation, and the prepared PLA/β-TCP scaffold exhibits a significant ability to enhance the osteogenic differentiation of MC3T3-E1 cells in vitro.Discussion: 3D printed LCD photocuring PLA/β-TCP scaffolds could improve surface bioactivity and lead to better osteogenesis, which may provide a unique strategy for developing bioactive implants in orthopedic applications.

Biocomposite films based on PLA reinforced with different β-TCP contents (10%, 20%, and 25%wt.) were fabricated via solvent casting and immersed in SBF for 7, 14, and 21 days. The bioactivity, morphological, and thermal behavior of composites with immersion were studied using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) microanalysis, weight loss (WL), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). This broad analysis leads to a deeper understanding of the evolution of the polymer–filler interaction with the degradation of the biocomposites. The results showed that β-TCP gradually evolved into carbonated hydroxyapatite as the immersion time increased. This evolution affected the interaction of β-TCP with PLA. PLA and β-TCP interactions differed from PLA and carbonated hydroxyapatite interactions. It was observed that β-TCP inhibited PLA hydrolysis but accelerated the thermal degradation of the polymer. β-TCP retarded the cold crystallization of PLA and hindered its crystallinity. However, after immersion in SBF, particles accelerated the cold crystallization of PLA. Therefore, considering the evolution of β-TCP with immersion in SBF is crucial for an accurate analysis of the biocomposites' degradation. These findings enhance the comprehension of the degradation mechanism in PLA/β-TCP, which is valuable for predicting the degradation performance of PLA/β-TCP in medical applications. [ABSTRACT FROM AUTHOR]

Introduction: Bone defects remain a thorny challenge that clinicians have to face. At present, scaffolds prepared by 3D printing are increasingly used in the field of bone tissue repair. Polylactic acid (PLA) has good thermoplasticity, processability, biocompatibility, and biodegradability, but the PLA is brittle and has poor osteogenic performance. Beta-tricalcium phosphate (β-TCP) has good mechanical properties and osteogenic induction properties, which can make up for the drawbacks of PLA. Methods: In this study, photocurable biodegradable polylactic acid (bio-PLA) was utilized as the raw material to prepare PLA/β-TCP slurries with varying β-TCP contents (β-TCP dosage at 0%, 10%, 20%, 30%, 35% of the PLA dosage, respectively). The PLA/β-TCP scaffolds were fabricated using liquid crystal display (LCD) light-curing 3D printing technology. The characterization of the scaffolds was assessed, and the biological activity of the scaffold with the optimal compressive strength was evaluated. The biocompatibility of the scaffold was assessed through CCK-8 assays, hemocompatibility assay and live-dead staining experiments. The osteogenic differentiation capacity of the scaffold on MC3T3-E1 cells was evaluated through alizarin red staining, alkaline phosphatase (ALP) detection, immunofluorescence experiments, and RT-qPCR assays. Results: The prepared scaffold possesses a three-dimensional network structure, and with an increase in the quantity of β-TCP, more β-TCP particles adhere to the scaffold surface. The compressive strength of PLA/β-TCP scaffolds exhibits a trend of initial increase followed by decrease with an increasing amount of β-TCP, reaching a maximum value of 52.1 MPa at a 10% β-TCP content. Degradation rate curve results indicate that with the passage of time, the degradation rate of the scaffold gradually increases, and the pH of the scaffold during degradation shows an alkaline tendency. Additionally, Live/dead staining and blood compatibility experiments suggest that the prepared PLA/β-TCP scaffold demonstrates excellent biocompatibility. CCK-8 experiments indicate that the PLA/β-TCP group promotes cell proliferation, and the prepared PLA/β-TCP scaffold exhibits a significant ability to enhance the osteogenic differentiation of MC3T3-E1 cells in vitro . Discussion: 3D printed LCD photocuring PLA/β-TCP scaffolds could improve surface bioactivity and lead to better osteogenesis, which may provide a unique strategy for developing bioactive implants in orthopedic applications., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Ye, Chen, Zhang, Zeng, Liu, Tan and Jie.)

Poly(lactic acid) (PLA) twisted yarn was braided into a 6-layered, hollow, cylindrical braid on a 16-spindle braid machine. The PLA braid was then placed inside a β-TCP tube, forming the PLA/β-TCP complex tube which imitates the porous structure of sponge bone. Different components and structures were studied to determine the best bone molding material. The β-TCP tube was created by sintering TCP powder mixed with stearic acid in a ratio of 1:1.5 to form a highly porous and well-structured tube with interconnected pores; its resulting porosity was 85.8 ± 0.93%. The PLA/β-TCP complex tube was implanted in a rabbit's femur and after 3 months a marrow cavity was discovered at the tube's core. New bone was also observed, regenerating around the PLA braid within the PLA/β-TCP complex tube. [ABSTRACT FROM AUTHOR]

Guided-bone regeneration (GBR) is increasingly using three-dimensional (3D) printing by fused deposition modeling (FDM) to build the filaments used for treatment. Polylactic acid (PLA) and beta-tricalcium phosphate (β-TCP) are widely used as base materials in 3D printing, necessitating that they are studied together in the context of GBR treatment. This study sought to test and compare the properties and efficacy of different ratios of β-TCP and PLA used to make the 3D-printed filament material to find the most effective combination of materials for GBR treatment. Several ratios of PLA to β-TCP were tested, including PLA/β-TCP ratios of 95%/5% (PLA-5), 90%/10% (PLA-10), 85%/15% (PLA-15), and 80%/20% (PLA-20), and quantitative real-time polymerase chain reaction (qPCR) in vitro testing was done to characterize the material. After adding β-TCP to PLA, mechanical testing indicated that tensile and elongation strengths decreased, hardness was retained, and cell proliferation was promoted. The effect of PLA and β-TCP on increasing alkaline phosphatase (ALP) activity was significantly greater in a ratio of 10% β-TCP/90% PLA at 5 days (p < 0.05) than in any other ratios tested. This is supported by results from qPCR testing, which showed early osteoblast-like differentiation of DLX5, RUNX2, OPG, OC, and collagen type 1 (COL-1) expression levels similar to cells cultured on PLA-10. Our results demonstrated that 3D printing of filaments produced in a ratio of 90% PLA to 10% β-TCP was more effective for GBR than that of filaments produced only using PLA.

In this study, poly(lactic acid) (PLA) and PLA/β‐tricalcium phosphate (TCP) biocomposites were developed by melt compounding using an internal melt mixer with three different TCP contents (5, 10, and 25 wt%). A comprehensive analysis of the thermal, rheological, and mechanical properties of these biocomposites was performed. TCP presented proper distribution in the PLA/TCP biocomposites: PLA5TCP and PLA10TCP exhibited rheological behavior similar to that of neat PLA. However, PLA25TCP presented significant agglomeration and reduction in thermal stability. Addition of TCP to the biocomposites enhanced their bioactivity and biocompatibility. The bioactivity assay was conducted by immersing the samples in SBF solution for 7 and 21 days, and the SEM and XRD surface analyses of the PLA/TCP biocomposites presented evidence of carbonated hydroxyapatite formation. The biocompatibility assay was performed using the extract method until 7 days, and PLA10TCP presented improved relative cell viability compared with the control. Finally, since the materials presented suitable thermal and rheological properties, filaments for additive manufacturing (AM) were developed, and they were used to produce screw models for bone‐ligament fixation. The 3D printed screws exhibited excellent printability and accuracy. Therefore, the PLA/TCP biocomposites developed can be used in further biomedical applications using AM, namely, guided bone tissue engineering. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) and beta‐tricalcium phosphate (β‐TCP) are biodegradable biomaterials that can be used in the field of bone fixation. This article aims to investigate the effect of equal channel angular pressing (ECAP) on the mechanical property, physical properties and in vitro degradation behaviors of PLA/β‐TCP (0, 10, and 20 wt%) composites. The bending strength of PLA, PLA/10TCP, and PLA/20TCP composites processed by ECAP were 158, 154, and 137 MPa, respectively, which is higher than its initial samples by 62.8%, 32.7%, and 55.6%. The degradation experiment was carried out in Sorensen's phosphate‐buffered solution at 37°C for 24 weeks. The weight loss rate of PLA/β‐TCP composites processed by ECAP increased fastly but its mechanical property decreased slowly in contrast with hot‐pressed samples. With the degradation proceeding, the existence of β‐TCP resulted in the formation of whisker‐like hydroxyapatite on the surface of PLA/10TCP and PLA/20TCP composites. The oriented fiber structure of PLA matrix disappeared and its internal structure became loose after soaking for 24 weeks. The fiber structure of the PLA/β‐TCP composites formed in the process of ECAP not only increased the initial strength and the degradation rate, but also maintained the mechanical property of the samples in the degradation process. In the meanwhile, the existence of β‐TCP could inhibit the degradation of PLA matrix composites. This study on the in vitro degradation of self‐reinforced PLA/β‐TCP composites prepared by ECAP will provide theoretical support for the development of bone fixation. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) has been extensively used in tissue engineering. However, poor mechanical properties and low cell affinity have limited its pertinence in load bearing bone tissue regeneration (BTR) devices.Augmenting PLA with β-Tricalcium Phosphate (β-TCP), a calcium phosphate-based ceramic, could potentially improve its mechanical properties and enhance its osteogenic potential.Gels of PLA and β-TCP were prepared of different % w/w ratios through polymer dissolution in acetone, after which polymer-ceramic membranes were synthesized using the gel casting workflow and subjected to characterization.Gel-cast polymer-ceramic constructs were associated with significantly higher osteogenic capacity and calcium deposition in differentiated osteoblasts compared to pure polymer counterparts. Immunocytochemistry revealed cell spreading over the gel-cast membrane surfaces, characterized by trapezoidal morphology, distinct rounded nuclei, and well-aligned actin filaments. However, groups with higher ceramic loading expressed significantly higher levels of osteogenic markers relative to pure PLA membranes. Rule of mixtures and finite element models indicated an increase in theoretical mechanical strength with an increase in β-TCP concentration.This study potentiates the use of PLA/β-TCP composites in load bearing BTR applications and the ability to be used as customized patient-specific shape memory membranes in guided bone regeneration. [ABSTRACT FROM AUTHOR]

This work presents the successful production of highly porous 3D nanofibrous hybrid scaffolds of polylactic acid (PLA)/polyethylene glycol (PEG) blends with the incorporation of calcium phosphate (CaP) bioceramics by a facile two-step process using the solution blow spinning (SBS) technique. CaP nanofibers were obtained at two calcium/phosphorus (Ca/P) ratios, 1.67 and 1.1, by SBS and calcination at 1000 °C. They were incorporated in PLA/PEG blends by SBS at 10 and 20 wt% to form 3D hybrid cotton-wool-like scaffolds. Morphological analysis showed that the fibrous scaffolds obtained had a randomly interconnected and highly porous structure. Also, the mean fiber diameter ranged from 408 ± 141 nm to 893 ± 496 nm. Apatite deposited considerably within 14 days in a simulated body fluid (SBF) test for hybrid scaffolds containing a mix of hydroxyapatite (HAp) and tri-calcium phosphate-β (β-TCP) phases. The scaffolds with 20 wt% CaP and a Ca/P ration of 1.1 showed better in vitro bioactivity to induce calcium mineralization for bone regeneration. Cellular tests evidenced that the developed scaffolds can support the osteogenic differentiation and proliferation of pre-osteoblastic MC3T3-E1 cells into mature osteoblasts. The results showed that the developed 3D scaffolds have potential applications for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Background: The deformation of oral and maxillofacial region leads to not only the damage of morphology and function, but also a series of aesthetic and psychological problems, severely affecting the quality of life of patients. Oral tissue engineering refers to developing biomaterials for repair or regeneration, with the application of tissue engineering technologies. This has become an area of increasing prominence. Current biologically inert materials are insufficient to fulfill clinical requirements. Therefore, tissue-engineered biomaterials with bioactive, even bionic properties are desperately needed. Main body: The complexity of the anatomy and the diversity of tissue types of oral and maxillofacial region pose great challenges to the regeneration, in the aspects of both biomaterials and manufacturing technologies. Biomaterials in clinical practice or research have evolved from natural materials to synthetic materials, from homogeneous materials to multiple composite materials. And now composite materials have increasingly demonstrated their advantages in terms of physicochemical and biological properties over conventional materials. In terms of manufacturing, traditional coating, sintering, and milling technologies can no longer satisfy the requirements for high-precision bionic structures of oral-tissue-engineering biomaterials. Scientists have turned to biofabrication technologies such as microfluidics and additive manufacturing. Short conclusion: This review aims to summarize the noteworthy advancements made in biomaterials of oral tissue engineering. We outlined the current biomaterials and manufacturing technologies and focused on various applications of these materials that may be connected to clinical treatment and research. We also suggested the future direction of development for biomaterials in oral tissue engineering. In future, biomaterials characterized by precision, functionalization, and individualization will be manufactured through digital, microfluidic, and 3D printing technologies. [ABSTRACT FROM AUTHOR]

Bone defects caused by tumors section, traffic accidents, and surgery remain a challenge in clinical. The drawbacks of traditional autografts and allografts limit their clinical application. 3D printed porous scaffolds have monumental potential to repair bone defects but still cannot effectively promote bone formation. Nano tantalum (Ta) has been reported with effective osteogenesis capability. Herein, we fabricated 3D printed PLA/β-TCP scaffold by using the fused deposition modeling (FDM) technique. Ta was doped on the surface of scaffolds utilizing the surface adhesion ability of polydopamine to improve its properties. The constructed PLA/β-TCP/PDA/Ta had good physical properties. In vitro studies demonstrated that the PLA/β-TCP/PDA/Ta scaffolds considerably promote cell proliferation and migration, and it additionally has osteogenic properties. Therefore, Ta doped 3D printed PLA/β-TCP/PDA/Ta scaffold could incontestably improve surface bioactivity and lead to better osteogenesis, which may provide a unique strategy to develop bioactive bespoke implants in orthopedic applications. [ABSTRACT FROM AUTHOR]

Bone tissue exhibits self-healing properties; however, not all defects can be repaired without surgical intervention. Bone tissue engineering offers artificial scaffolds, which can act as a temporary matrix for bone regeneration. The aim of this study was to manufacture scaffolds made of poly(lactic acid), poly(ε-caprolactone), poly(propylene fumarate), and poly(ethylene glycol) modified with bioglass, beta tricalcium phosphate (TCP), and/or wollastonite (W) particles. The scaffolds were fabricated using a gel-casting method and observed with optical and scanning electron microscopes. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG), wettability, and degradation tests were conducted. The highest content of TCP without W in the composition caused the highest hydrophilicity (water contact angle of 61.9 ± 6.3°), the fastest degradation rate (7% mass loss within 28 days), moderate ability to precipitate CaP after incubation in PBS, and no cytotoxicity for L929 cells. The highest content of W without TCP caused the highest hydrophobicity (water contact angle of 83.4 ± 1.7°), the lowest thermal stability, slower degradation (3% mass loss within 28 days), and did not evoke CaP precipitation. Moreover, some signs of cytotoxicity on day 1 were observed. The samples with both TCP and W showed moderate properties and the best cytocompatibility on day 4. Interestingly, they were covered with typical cauliflower-like hydroxyapatite deposits after incubation in phosphate-buffered saline (PBS), which might be a sign of their excellent bioactivity. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is widely used in the field of medicine due to its biocompatibility, versatility, and cost-effectiveness. Three-dimensional (3D) printing or the systematic deposition of PLA in layers has enabled the fabrication of customized scaffolds for various biomedical and clinical applications. In tissue engineering and regenerative medicine, 3D-printed PLA has been mostly used to generate bone tissue scaffolds, typically in combination with different polymers and ceramics. PLA's versatility has also allowed the development of drug-eluting constructs for the controlled release of various agents, such as antibiotics, antivirals, anti-hypertensives, chemotherapeutics, hormones, and vitamins. Additionally, 3D-printed PLA has recently been used to develop diagnostic electrodes, prostheses, orthoses, surgical instruments, and radiotherapy devices. PLA has provided a cost-effective, accessible, and safer means of improving patient care through surgical and dosimetry guides, as well as enhancing medical education through training models and simulators. Overall, the widespread use of 3D-printed PLA in biomedical and clinical settings is expected to persistently stimulate biomedical innovation and revolutionize patient care and healthcare delivery. [ABSTRACT FROM AUTHOR]

In exploring the challenges of bone repair and regeneration, this review evaluates the potential of bone tissue engineering (BTE) as a viable alternative to traditional methods, such as autografts and allografts. Key developments in biomaterials and scaffold fabrication techniques, such as additive manufacturing and cell and bioactive molecule-laden scaffolds, are discussed, along with the integration of bio-responsive scaffolds, which can respond to physical and chemical stimuli. These advancements collectively aim to mimic the natural microenvironment of bone, thereby enhancing osteogenesis and facilitating the formation of new tissue. Through a comprehensive combination of in vitro and in vivo studies, we scrutinize the biocompatibility, osteoinductivity, and osteoconductivity of these engineered scaffolds, as well as their interactions with critical cellular players in bone healing processes. Findings from scaffold fabrication techniques and bio-responsive scaffolds indicate that incorporating nanostructured materials and bioactive compounds is particularly effective in promoting the recruitment and differentiation of osteoprogenitor cells. The therapeutic potential of these advanced biomaterials in clinical settings is widely recognized and the paper advocates continued research into multi-responsive scaffold systems. [ABSTRACT FROM AUTHOR]

A novel regression model, monotonic inner relation-based non-linear partial least squares (MIR-PLS), is proposed to address complex issues like limited observations, multicollinearity, and nonlinearity in Chinese Medicine (CM) dose-effect relationship experimental data. MIR-PLS uses a piecewise mapping function based on monotonic cubic splines to model the non-linear inner relations between input and output score vectors. Additionally, a new weight updating strategy (WUS) is developed by leveraging the properties of monotonic functions. The proposed MIR-PLS method was compared with five well-known PLS variants: standard PLS, quadratic PLS (QPLS), error-based QPLS (EB-QPLS), neural network PLS (NNPLS), and spline PLS (SPL-PLS), using CM dose-effect relationship datasets and near-infrared (NIR) spectroscopy datasets. Experimental results demonstrate that MIR-PLS exhibits general applicability, achieving excellent predictive performances in the presence or absence of significant non-linear relationships. Furthermore, the model is not limited to CM dose-effect relationship research and can be applied to other regression tasks. [ABSTRACT FROM AUTHOR]

Background: Bioresorbable patient-specific additive-manufactured bone grafts, meshes, and plates are emerging as a promising alternative that can overcome the challenges associated with conventional off-the-shelf implants. The fabrication of patient-specific implants (PSIs) directly at the point-of-care (POC), such as hospitals, clinics, and surgical centers, allows for more flexible, faster, and more efficient processes, reducing the need for outsourcing to external manufacturers. We want to emphasize the potential advantages of producing bioresorbable polymer implants for cranio-maxillofacial surgery at the POC by highlighting its surgical applications, benefits, and limitations. Methods: This study describes the workflow of designing and fabricating degradable polymeric PSIs using three-dimensional (3D) printing technology. The cortical bone was segmented from the patient's computed tomography data using Materialise Mimics software, and the PSIs were designed created using Geomagic Freeform and nTopology software. The implants were finally printed via Arburg Plastic Freeforming (APF) of medical-grade poly (L-lactide-co-D, L-lactide) with 30% β-tricalcium phosphate and evaluated for fit. Results: 3D printed implants using APF technology showed surfaces with highly uniform and well-connected droplets with minimal gap formation between the printed paths. For the plates and meshes, a wall thickness down to 0.8 mm could be achieved. In this study, we successfully printed plates for osteosynthesis, implants for orbital floor fractures, meshes for alveolar bone regeneration, and bone scaffolds with interconnected channels. Conclusions: This study shows the feasibility of using 3D printing to create degradable polymeric PSIs seamlessly integrated into virtual surgical planning workflows. Implementing POC 3D printing of biodegradable PSI can potentially improve therapeutic outcomes, but regulatory compliance must be addressed. [ABSTRACT FROM AUTHOR]

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In recent years, the exploration of sustainable alternatives in the field of bone tissue engineering has led researchers to focus on marine waste byproducts as a valuable resource. These marine resources, often overlooked remnants of various industries, exhibit a rich composition of hydroxyapatite, collagen, calcium carbonate, and other minerals essential to the complex framework of bone structure. Marine waste by-products can emit gases such as methane and carbon dioxide, highlighting the urgency to repurpose these materials for innovative tissue regeneration solutions, offering a sustainable approach to address environmental challenges while advancing medical science. Using these discarded materials offers a promising pathway for sustainable development in regenerative medicine. This review investigates the distinctive properties of marine waste byproducts, emphasizing their capacity to be recycled effectively to contribute to the rebuilding of bone and cartilage tissue during regeneration processes. We also highlight the compatibility of these resources with biological materials such as platelet-rich plasma (PRP), stem cells, exosomes, and natural bioproducts, as well as nanoparticles (NPs) and polymers. By using the natural potential of these resources, we simultaneously address environmental challenges and promote innovative solutions in skeletal tissue engineering, initiating a new era of environmentally green biomedical research., (© 2024 Wiley Periodicals LLC.)

The proposed strategy for the extrusion of printable composite filaments follows the favourable association of biogenic hydroxyapatite (HA) and graphene nanoplatelets (GNP) as reinforcement materials for a poly(lactic acid) (PLA) matrix. HA particles were chosen in the <40 μm range, while GNP were selected in the micrometric range. During the melt–mixing incorporation into the PLA matrix, both reinforcement ratios were simultaneously modulated for the first time at different increments. Cylindrical composite pellets/test samples were obtained only for the mechanical and wettability behaviour evaluation. The Fourier-transformed infrared spectroscopy depicted two levels of overlapping structures due to the solid molecular bond between all materials. Scanning electron microscopy and surface wettability and mechanical evaluations vouched for the (1) uniform/homogenous dispersion/embedding of HA particles up to the highest HA/GNP ratio, (2) physical adhesion at the HA-PLA interface due to the HA particles' porosity, (3) HA-GNP bonding, and (4) PLA-GNP synergy based on GNP complete exfoliation and dispersion into the matrix. [ABSTRACT FROM AUTHOR]

Bone tissue is one of the most transplanted tissues. The ageing population and bone diseases are the main causes of the growing need for novel treatments offered by bone tissue engineering. Three-dimensional (3D) scaffolds, as artificial structures that fulfil certain characteristics, can be used as a temporary matrix for bone regeneration. In this study, we aimed to fabricate 3D porous polymer scaffolds functionalized with tricalcium phosphate (TCP) particles for applications in bone tissue regeneration. Different combinations of poly(lactic acid) (PLA), poly(ethylene glycol) (PEG with molecular weight of 600 or 2000 Da) and poly(ε-caprolactone) (PCL) with TCP were blended by a gel-casting method combined with rapid heating. Porous composite scaffolds with pore sizes from 100 to 1500 µm were obtained. ATR-FTIR, DSC, and wettability tests were performed to study scaffold composition, thermal properties, and hydrophilicity, respectively. The samples were observed with the use of optical and scanning electron microscopes. The addition of PCL to PLA increased the hydrophobicity of the composite scaffolds and reduced their susceptibility to degradation, whereas the addition of PEG increased the hydrophilicity and degradation rates but concomitantly resulted in enhanced creation of rounded mineral deposits. The scaffolds were not cytotoxic according to an indirect test in L929 fibroblasts, and they supported adhesion and growth of MG-63 cells when cultured in direct contact. [ABSTRACT FROM AUTHOR]

Calcium phosphate-based synthetic bone is broadly used for the clinical treatment of bone defects caused by trauma and bone tumors. Synthetic bone is easy to use; however, its effects depend on the size and location of the bone defect. Many alternative treatment options are available, such as joint arthroplasty, autologous bone grafting, and allogeneic bone grafting. Although various biodegradable polymers are also being developed as synthetic bone material in scaffolds for regenerative medicine, the clinical application of commercial synthetic bone products with comparable performance to that of calcium phosphate bioceramics have yet to be realized. This review discusses the status quo of bone-regeneration therapy using artificial bone composed of calcium phosphate bioceramics such as β-tricalcium phosphate (βTCP), carbonate apatite, and hydroxyapatite (HA), in addition to the recent use of calcium phosphate bioceramics, biodegradable polymers, and their composites. New research has introduced potential materials such as octacalcium phosphate (OCP), biologically derived polymers, and synthetic biodegradable polymers. The performance of artificial bone is intricately related to conditions such as the intrinsic material, degradability, composite materials, manufacturing method, structure, and signaling molecules such as growth factors and cells. The development of new scaffold materials may offer more efficient bone regeneration. [ABSTRACT FROM AUTHOR]

Typical electrospun polylactic acid (PLA) membranes revealing potential hydrophobicity and inflammation from acid release during degradation are major drawbacks as an ideal guided tissue regeneration (GTR) barrier. This study investigated the in vitro degradation properties of electrospun PLA/beta-tricalcium phosphate (β-TCP) membranes treated by polyethylene oxide dip-coating process. After surface modification, the membranes revealed good wettability in contact angle measurement. The addition of β-TCP can render good pH buffering properties for electrospun PLA membranes during the in vitro degradation test. The mechanical properties of the hybrid membrane showed no significant difference in suture pullout force at a dried or wetted state. For cell adhesion and proliferation, the membranes with hydrophilicity can enhance the cell attachment at early stage. Overall, these results show that electrospinning combined with dip coating is a feasible processing technology for producing hydrophilic fibrous GTR membranes. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers. [ABSTRACT FROM AUTHOR]

The skeleton is a highly innervated organ in which nerve fibers interact with various skeletal cells. Peripheral nerve endings release neurogenic factors and sense skeletal signals, which mediate bone metabolism and skeletal pain. In recent years, bone tissue engineering has increasingly focused on the effects of the nervous system on bone regeneration. Simultaneous regeneration of bone and nerves through the use of materials or by the enhancement of endogenous neurogenic repair signals has been proven to promote functional bone regeneration. Additionally, emerging information on the mechanisms of skeletal interoception and the central nervous system regulation of bone homeostasis provide an opportunity for advancing biomaterials. However, comprehensive reviews of this topic are lacking. Therefore, this review provides an overview of the relationship between nerves and bone regeneration, focusing on tissue engineering applications. We discuss novel regulatory mechanisms and explore innovative approaches based on nerve–bone interactions for bone regeneration. Finally, the challenges and future prospects of this field are briefly discussed. [ABSTRACT FROM AUTHOR]

PLA/HAP composites have attracted significant attention in material science, especially in the field of biomaterials. However, these composites have suffered from unfavorable interface interactions between PLA and HAP interfaces, which limits the applications. In this study, we aimed to improve the interface interactions of PLA/HAP composite by modifying the HAP surface. For this purpose, HAP particles were functionalized with three different silane modifying agents, including (3-Aminopropyl)trimethoxysilane (AMMO), (3-glycidyloxypropyl)trimethoxysilane (GLYMO) and (3-triethoxysilyl)propylsuccinic anhydride (GF-20). The obtained modified HAP (m-HAP) were used to prepare PLA/m-HAP. Interface interactions of composites were characterized by Fourier transform infrared spectrophotometer (FT-IR) and differential scanning calorimetry (DSC). In addition, Vickers hardness tests were performed to reveal the effect of silane modifying agents on hardness before and after the in vitro degradation test. [ABSTRACT FROM AUTHOR]