Bone Tissue Engineering Applications Research Articles

Synthetic strategy for the production of electrically polarized polyvinylidene fluoride-trifluoroethylene-co-polymer osseo-functionalized with hydroxyapatite scaffold.

The physiological mechanism of bone tissue regeneration is intricately organized and involves several cell types, intracellular, and extracellular molecular signaling networks. To overcome the drawbacks of autografts and allografts, a number of synthetically produced scaffolds have been manufactured by integrating ceramics, polymers, and their hybrid-composites. Considering the fact that natural bone is composed primarily of collagen and hydroxyapatite, ceramic-polymer composite materials seem to be the most viable alternative to bone implants. Here, in this experimental study, copolymer PVDF-TrFE has been amalgamated with HA ceramics to produce composite scaffolds as bone implants. In order to fabricate PVDF-TrFE-HA (polyvinylidene fluoride-trifluoroethylene-hydroxyapatite) composite scaffolds, solvent casting-particulate leaching technique was devised. Two scaffold specimens were produced, with different PVDF-TrFE and HA molar ratios (70:30 and 50:50), and then electrically polarized to observe the subsequent polarization impact on the tissue growth and the suppression of bacterial cell proliferation. Both the specimens underwent characterization to analyze their biocompatibility and bactericidal activities. The bacterial culture of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) bacteria on the composites was studied to understand the antibacterial characteristics. Moreover, MG63 cells cultured on these as-formed composites provided information about osteogenesis. Improved osteogenesis and antibacterial efficacy were observed on both the composites. However, the composite with 70 wt% PVDF-TrFE and 30 wt% HA showed a higher bactericidal effect as well as osteogenesis. It was found that PVDF-TrFE-HA-based biomaterials have the potential for bone tissue engineering applications.

Influence of size and crystallinity of nanohydroxyapatite (nHA) particles on the properties of Polylactic Acid/nHA nanocomposite scaffolds produced by 3D printing

Polylactic acid (PLA) and hydroxyapatite (HA) composite scaffolds have been widely studied for applications in bone tissue engineering (BTE) due to their bioactive and biocompatible properties. However, there is a need for more knowledge about the influence of size and crystallinity of HA nanoparticles (nHA) on the properties of PLA/nHA nanocomposite scaffolds produced by 3D printing. In this study, 3D printing was used to produce PLA nanocomposite scaffolds incorporated with nHA filler with different particle sizes and crystallinities. Initially, the nanocomposites were prepared by casting for 3D printing of scaffolds, which were characterized by analysis of thermal, morphological, physical-chemical, mechanical, and biological properties in vitro. The results showed that the size and crystallinity of nHA particles mainly influenced the scaffolds' mechanical properties, degradation rate, and bioactivity. Incorporating nHA provided a gain in compressive strength compared to pure PLA, superior to natural cancellous bone, which varies between 2 and 12 MPa. The lower crystallinity, 39.46 %, promoted a higher rate of degradation and bioactivity in vitro due to its solubility in the simulated fluid. All nanocomposite scaffolds showed cell viability above 90 %. The scaffolds showed suitable properties for BTE applications.

Magnetic biocomposite scaffold based on decellularized tendon ECM and MNP-deposited halloysite nanotubes: physicochemical, thermal, rheological, mechanical and in vitro biological evaluations

The development of new three-dimensional biomaterials with advanced versatile properties is critical to the success of tissue engineering (TE) applications. Here, (a) bioactive decellularized tendon extracellular matrix (dECM) with a sol-gel transition feature at physiological temperature, (b) halloysite nanotubes (HNT) with known mechanical properties and bioactivity, and (c) magnetic nanoparticles (MNP) with superparamagnetic and osteogenic properties were combined to develop a new scaffold that could be used in prospective bone TE applications. Deposition of MNPs on HNTs resulted in magnetic nanostructures without agglomeration of MNPs. A completely cell-free, collagen- and glycosaminoglycan- rich dECM was obtained and characterized. dECM-based scaffolds incorporated with 1%, 2% and 4% MNP-HNT were analysed for their physical, chemical, and in vitro biological properties. Fourier-transform infrared spectroscopy, x-ray powder diffractometry and vibrating sample magnetometry analyses confirmed the presence of dECM, HNT and MNP in all scaffold types. The capacity to form apatite layer upon incubation in simulated body fluid revealed that dECM-MNP-HNT is a bioactive material. Combining dECM with MNP-HNT improved the thermal stability and compressive strength of the macroporous scaffolds upto 2% MNP-HNT. In vitro cytotoxicity and hemolysis experiments showed that the scaffolds were essentially biocompatible. Human bone marrow mesenchymal stem cells adhered and proliferated well on the macroporous constructs containing 1% and 2% MNP-HNT; and remained metabolically active for at least 21 d in vitro. Collectively, the findings support the idea that magnetic nanocomposite dECM scaffolds containing MNP-HNT could be a potential template for TE applications.

Effect of graphene oxide/ poly-L-lactic acid composite scaffold on the biological properties of human dental pulp stem cells

BackgroundTissue engineering has attracted recent attention as a promising bone repair and reconstruction approach. Dental pulp stem cells (DPSCs) are pluripotent and can differentiate into bone cells with the correct environment and substrate. Therefore, suitable scaffold materials are essential for fabricating functional three-dimensional (3D) tissue and tissue regeneration. Composite scaffolds consisting of biodegradable polymers are very promising constructs. This study aims to verify the biological function of human DPSCs seeded onto composite scaffolds based on graphene oxide (GO) and poly-L-lactic acid (PLLA).MethodsThe surface morphology was observed under scanning electron microscopy (SEM). Chemical composition was evaluated with Fourier transform infrared (FTIR) spectroscopy. The biocompatibility of GO/PLLA scaffolds was assessed using phalloidin staining of cytoskeletal actin filaments, live/dead staining, and a CCK-8 assay. The effect of GO/PLLA scaffolds on cell osteogenic differentiation was detected through ALP staining, ALP activity assays, and alizarin red S staining, complemented by quantitative real-time PCR (qRT-PCR) analysis.ResultsOur data showed that GO and PLLA are successfully integrated and the GO/PLLA scaffolds exhibit favorable bioactivity and biocompatibility towards DPSCs. Additionally, it was observed that the 0.15% GO/PLLA scaffold group promoted DPSC proliferation and osteogenic differentiation by forming more calcium nodules, showing a higher intensity of ALP staining and ALP activity, and enhancing the expression levels of differentiation marker genes RUNX2 and COL1.ConclusionsThese results demonstrate that the GO/PLLA scaffold is a feasible composite material suitable for cell culture and holds promising applications for oral bone tissue engineering.

The design of natural hybrid biomaterial to promote osteogenic differentiation, collagen i and II expression and relief of musculoskeletal pains: Bone tissue-engineering applications (in-vitro and clinical studies)

This research aimed to fabricate a natural hybrid biomaterial and assess its physicochemical/biological properties to study the role of the therapeutic biomaterial in the growth of human monocytes, synoviocytes, chondrocytes, expression of type-I/II collagen, and osteogenic differentiation for bone tissue engineering applications, as well as to assess effects of bio-ointment derived from this biomaterial on relief of musculoskeletal pains. Hence, an oily formula [turmeric:ginger:chili pepper:rose oils (1:1:1:1w/w)] was mixed with the base oil [sesame:black seed:olive oils (1:0.4:0.6w/w)] in 3 wt ratios of 1:6(H1), 1.5:5.5(H2), and 2:5(H3). Accordingly, H2 indicated a better performance in cell growth and decrease of inflammatory mediators and led to the highest expression of osteoblastic genes of RUNX2, OCN, and OPN, as well as collagen I and II (COL1A1,COL2A) respectively 1.3-fold, 1.7-fold, and 1.4-fold, as well as %87 % and ∼ 60 % higher than H1, and ∼ 2-fold, 2.1-fold, and 3.4-fold, and ∼ 19 % and ∼ 16 % higher than H3. A clinical study on H2 was also performed on 50 patients with musculoskeletal pains. H2-based bio-ointment could relieve pain in less than 10 min for 40 % of patients and after 30 min from use for 35 %. Moreover, the analgesia period for 60 % and 36 % of patients lasted for longer than 3 h and between 2 h and 3 h, respectively. 76 % also stated that bio-ointment possesses stronger effects than other treatments along with moderate warming functions. Finally, although 6 % of patients reported mild effectiveness in pain relief, 92 % of users stated this therapeutic method has resulted in more effects on their pain relief and damaged organ performance recovery.

3D printed β-tricalcium phosphate versus synthetic bone mineral scaffolds: A comparative in vitro study of biocompatibility

BACKGROUND: β-tricalcium phosphate (β-TCP) has been successfully utilized as a 3D printed ceramic scaffold in the repair of non-healing bone defects; however, it requires the addition of growth factors to augment its regenerative capacity. Synthetic bone mineral (SBM) is a novel and extrudable carbonate hydroxyapatite with ionic substitutions known to facilitate bone healing. However, its efficacy as a 3D printed scaffold for hard tissue defect repair has not been explored. OBJECTIVE: To evaluate the biocompatibility and cell viability of human osteoprecursor (hOP) cells seeded on 3D printed SBM scaffolds via in vitro analysis. METHODS: SBM and β-TCP scaffolds were fabricated via 3D printing and sintered at various temperatures. Scaffolds were then subject to qualitative cytotoxicity testing and cell proliferation experiments utilizing (hOP) cells. RESULTS: SBM scaffolds sintered at lower temperatures (600 °C and 700 °C) induced greater levels of acute cellular stress. At higher sintering temperatures (1100 °C), SBM scaffolds showed inferior cellular viability relative to β-TCP scaffolds sintered to the same temperature (1100 °C). However, qualitative analysis suggested that β-TCP presented no evidence of morphological change, while SBM 1100 °C showed few instances of acute cellular stress. CONCLUSION: Results demonstrate SBM may be a promising alternative to β-TCP for potential applications in bone tissue engineering.

Design and Characterization of 3D Printed Pore Gradient Hydrogel Scaffold for Bone Tissue Engineering

Macroporous hydrogel scaffolds are widely used in tissue engineering to promote cell growth and proliferation. Aiming to enhance cell seeding efficiency and facilitate the osteodifferentiation of mesenchymal stem cells, this study demonstrates the fabrication of pore gradient biodegradable hydrogel scaffolds inspired by natural bone structures for bone tissue engineering applications. The scaffolds were fabricated via extrusion-based 3D printing, using sequential deposition of three customized Gelatin/Oxidized Alginate - based inks with subsequent cryogenic crosslinking for permanent structure fixation. The resulting constructs were characterized and featured a continuous gradient morphology with pore sizes ranging from 10 to 300 μm. The gradient scaffolds exhibited improved mechanical stability, with a compression resistance of 149 kPa, as opposed to the non-gradient scaffold’s 116 kPa at 70% strain, and a sustained degradation rate with only a 10% loss of its initial weight within three weeks. Gradient scaffolds demonstrated a doubling of cell seeding efficiency to 47% with dense and homogeneously distributed cellular layers, as evidenced by confocal and electron microscopy. Furthermore, the gradient scaffolds demonstrated superior osteodifferentiation, with significantly higher ALP and DMP1 production and enhanced extracellular matrix mineralization compared to gradientless macroporous scaffolds. This study provides insights into the design of macroporous scaffolds and emphasizes the advantages of pore gradient over homogeneous gradientless morphologies.

Novel polycaprolactone-based biomimetic grafts enriched with graphene oxide and cerium oxide: Exploring improved osteogenic potential

In bone tissue engineering, the development of advanced biomaterials is crucial to address the challenges associated with the treatment and regeneration of bone defects. This study presents a novel polymeric nanocomposite consisting of Polycaprolactone (PCL) integrated with graphene oxide (GO) and cerium oxide (CeO2) nanoparticles, aiming to comprehensively explore its multifaceted potential for bone tissue engineering applications. The physicochemical properties of the composite films were analyzed. Biodegradation studies showed superior degradability to pure PCL due to added hydrophilic features and increased nanofiller-induced surface porosity. The remarkable improvement in mechanical stability is attributed to the uniform dispersion of nanofillers. Assessments of surface wettability, demonstrate a noteworthy shift towards heightened hydrophilicity, rendering a more conducive environment for biomolecules. The hybrid polymer nanocomposite exhibits remarkable hemocompatibility, antibacterial properties, antioxidant activity, and excels in facilitating apatite deposition and promoting osteogenic differentiation. Biomineralization investigations and ARS assay underscore the nanocomposite's exceptional ability to promote apatite deposition, a pivotal mineral in bone formation, owing to the altered surface properties introduced by the nanofillers. The ALP findings imply that the PCL-GO-CeO2 nanocomposite actively supports and accelerates the process of osteogenic differentiation in MSCs, indicating its potential utility in bone tissue engineering. Additionally, cell culture studies conducted on HOS and rBMSC cell lines validate the nanocomposite's excellent cell viability, attachment, and proliferation, affirming its biocompatibility and potential for bone tissue engineering. Collectively, these findings establish PCL-GO-CeO2 nanocomposite as a favourable option for enhancing bone regeneration.

Optimizing microwave-assisted synthesis of akermanite nanoparticles using citric acid as a chelating agent: A combined machine learning and experimental approach

This study aims to synthesize akermanite (Ca2MgSi2O7) using an eco-friendly and fast microwave-assisted method and understand the effect of using citric acid (CA) as a chelating agent to optimize the calcination temperature for synthesizing pure akermanite nanoparticles (along with a trace amount of merwinite) at low calcination temperatures. This study developed a new predictive model by machine learning-assisted modeling to advance the understanding of relationship between synthesis parameters and the resulting purity and particle size of akermanite. To evaluate the reliability of the developed model in predicting the purity and characteristics of the resultant Ak powder, the crystallization behavior and phase formation sequence of citric acid-containing samples and those without citric acid were experimentally investigated by differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. Following validation and training, the developed model indicates promising effects of citric acid on reducing crystallization temperature, enhancing purity, and decreasing particle size. The synthesized powders were further characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM) analyses. For the first time, our results addressed the microwave-assisted synthesis as an effective method via experimental evidence and machine learning-assisted modeling that allows for the production of akermanite containing a trace amount of merwinite with the aid of citric acid at a relatively low calcination temperature of 950 °C. In vitro bioactivity evaluation supported the potential suitability of Ak powders for bone tissue engineering applications.

Effect of Graphite, Graphene Oxide, and Multi-Walled Carbon Nanotubes on the Physicochemical Characteristics and Biocompatibility of Chitosan/Hyaluronic Acid/Hydroxyapatite Scaffolds for Tissue Engineering Applications

Bone tissue engineering (BTE) is a promising alternative approach to the repair of damaged bone tissue. This study aims to fabricate and characterize scaffolds composed of chitosan (CS), hyaluronic acid (HA), hydroxyapatite (HAp), and a combination of graphite (Gr), graphene oxide (GO), and multi-walled carbon nanotubes (MWCNT) for BTE applications. The Gr and MWCNT were functionalized by acid oxidation, while the GO was synthesized using the improved Hummer method. The scaffolds were prepared by lyophilization, and the physical, chemical, and biological properties were evaluated. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, mechanical testing, water contact angle, degradation, and biocompatibility assays were used to characterize the scaffolds. The degradation rate was determined using the liquid displacement method. Pores of different sizes were present on the surface of and throughout the scaffold. According to the FTIR results, the scaffolds contained functional groups that promote cell differentiation and proliferation. These scaffolds have compressive strength, Young's modulus, and toughness similar to cancellous bone, with reasonable porosity and controllable degradation rates. Biocompatibility testing confirmed that the scaffolds support cell proliferation and differentiation.

Incorporating bioactive glass nanoparticles in silk fibroin/bacterial nanocellulose composite scaffolds improves their biological and osteogenic properties for bone tissue engineering applications

Blend polymers composed of natural polymers are a ubiquitous biomaterial class due to their suitable mechanical and biological characterization. In the present study, composite scaffolds based on bacterial cellulose (BC)/silk fibroin (SF) with bioactive glass nanoparticles (BGNPs) were developed to enhance osteogenesis in human adipose derived stem cells (hASCs). The scanning electron microscopy (SEM) results of BGNPs indicated a spherical morphology and size ranging from 15 to 30 nm. The presence of BC and BGNPs reduced the pore diameter of SF scaffolds to about 210 ± 10 μm and 205 ± 10 μm, respectively, while increasing their compressive strength and compressive modulus. FTIR analyses proved the presence of BGNPs, BC and SF in the scaffolds. Flow cytometry data confirmed the surface markers for hASCs. The results also showed that BC and BGNPs addition to BC/SF scaffolds decreased degradation and swelling rate. The gene expression (Runx2, alkaline phosphatase and osteocalcin) studies signified the osteogenic potential of BGNPs in BC/SF scaffolds on hASCs. Eventually, the increased cell adhesion, viability and differentiation in the BC/SF and BC/SF/BGNPs composite scaffolds drawn from MTT, SEM, Alizarin red staining and alkaline phosphatase activity confirmed that these scaffolds promise to serve as a therapeutic candidate for bone defects.

Strontium and Zinc Co-Doped Mesoporous Bioactive Glass Nanoparticles for Potential Use in Bone Tissue Engineering Applications.

Mesoporous bioactive glass nanoparticles (MBGNs) have attracted significant attention as multifunctional nanocarriers for various applications in both hard and soft tissue engineering. In this study, multifunctional strontium (Sr)- and zinc (Zn)-containing MBGNs were successfully synthesized via the microemulsion-assisted sol-gel method combined with a cationic surfactant (cetyltrimethylammonium bromide, CTAB). Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs exhibited spherical shapes in the nanoscale range of 100 ± 20 nm with a mesoporous structure. Sr and Zn were co-substituted in MBGNs (60SiO2-40CaO) to induce osteogenic potential and antibacterial properties without altering their size, morphology, negative surface charge, amorphous nature, mesoporous structure, and pore size. The synthesized MBGNs facilitated bioactivity by promoting the formation of an apatite-like layer on the surface of the particles after immersion in Simulated Body Fluid (SBF). The effect of the particles on the metabolic activity of human mesenchymal stem cells was concentration-dependent. The hMSCs exposed to Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs at 200 μg/mL enhanced calcium deposition and osteogenic differentiation without osteogenic supplements. Moreover, the cellular uptake and internalization of Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs in hMSCs were observed. These novel particles, which exhibited multiple functionalities, including promoting bone regeneration, delivering therapeutic ions intracellularly, and inhibiting the growth of Staphylococcus aureus and Escherichia coli, are potential nanocarriers for bone regeneration applications.

Numerical study on effect of process parameters on material extrusion 3D printing (ME3DP) for porous bone tissue engineering scaffolds

Bone tissue engineering (BTE) holds promise for treating bone defects, and 3D-printed porous scaffolds are pivotal for tissue regeneration. This study explores the impact of material extrusion 3D printing (ME3DP) process parameters (i.e., layer height and extrusion temperature) on 3D-printed porous scaffolds made of polyetherimide (PEI) material for BTE. The intricate relationships shaping scaffold dimensional accuracy, residual stresses, and warpage tendencies were unveiled using comprehensive numerical simulations. Our findings reveal that higher layer heights enhance dimensional stability, especially at lower printing temperatures, reducing maximum displacements. Consequently, lower layer heights lead to higher warpage critical values. This insight is instrumental in optimizing the material extrusion 3D printing (ME3DP) process, vital for precise net shape in BTE applications. Furthermore, residual stresses also revealed a correlation between higher printing temperatures and increased residual stresses. These findings emphasize the necessity of balancing material flow, printing temperature, and layer height for scaffold quality. Therefore, the right balance between precision and mechanical stability is critical for producing high-quality scaffolds that meet BTE requirements.

Properties of Carbonated Hydroxyapatite-Based Scaffold from Oyster Shells Composited with Honeycomb and Polyethylene Oxide for Bone Tissue Engineering Applications

Scaffold Carbonated Hydroxyapatite/Honeycomb/Polyethylene Oxide (CHA/HCB/PEO) has been obtained by freeze-drying. The bioceramic CHA used in this study was synthesized from oyster shells using precipitation. HCB and PEO were added as reinforcement materials that affect the crystallographic properties of the scaffold. This study aimed to determine the characteristics of the scaffolds for bone tissue engineering. CHA and scaffolds were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometer (XRD), and Scanning Electron Microscopy (SEM). FTIR spectra and XRD graphs confirmed that the CHA produced was B-type. FTIR spectra of the scaffold showed the presence of HCB and PEO in the scaffold, which means they were homogeneously bound in the scaffold solution. XRD test results show that scaffolds' crystallinity and crystallite size tends to decrease compared to CHA. This was good because they could make cells easier to proliferate. A small-scale pore structure (micropore) was also formed in the scaffold. The porosity and pore size of the scaffold were affected by the concentration of CHA. The presence of the micropores can increase the permeability of the scaffold and facilitate cell migration. Thus, the composition of CHA/HCB/PEO scaffolds can be a good candidate material in bone tissue engineering.

Chemical etching of Ti-6Al-4V biomaterials fabricated by selective laser melting enhances mesenchymal stromal cell mineralization.

Porous titanium scaffolds fabricated by powder bed fusion additive manufacturing techniques have been widely adopted for orthopedic and bone tissue engineering applications. Despite the many advantages of this approach, topological defects inherited from the fabrication process are well understood to negatively affect mechanical properties and pose a high risk if dislodged after implantation. Consequently, there is a need for further post-process surface cleaning. Traditional techniques such as grinding or polishing are not suited to lattice structures, due to lack of a line of sight to internal features. Chemical etching is a promising alternative; however, it remains unclear if changes to surface properties associated with such protocols will influence how cells respond to the material surface. In this study, we explored the response of bone marrow derived mesenchymal stem/stromal cells (MSCs) to Ti-6Al-4V whose surface was exposed to different durations of chemical etching. Cell morphology was influenced by local topological features inherited from the SLM fabrication process. On the as-built surface, topological nonhomogeneities such as partially adhered powder drove a stretched anisotropic cellular morphology, with large areas of the cell suspended across the nonhomogeneous powder interface. As the etching process was continued, surface defects were gradually removed, and cell morphology appeared more isotropic and was suggestive of MSC differentiation along an osteoblastic-lineage. This was accompanied by more extensive mineralization, indicative of progression along an osteogenic pathway. These findings point to the benefit of post-process chemical etching of additively manufactured Ti-6Al-4V biomaterials targeting orthopedic applications.

Fabrication of 3D porous polyurethane-graphene oxide scaffolds by a sequential two-step processing for non-load bearing bone defects

Bone defects as a common orthopedic disease lead to severe pains over a long period. Scaffolds are novel approaches in tissue engineering to treat bone problems and deal with their challenges. Here, 3D porous polyurethane (PU) scaffolds containing graphene oxide (GO) with different percentages (0, 0.1, 0.3, and 0.5 wt%) were developed through a combination of freeze-drying and salt etching techniques for bone tissue engineering applications. The morphologies of scaffolds, physicochemical properties, the degree of crystallinity, and hydrophilicity were evaluated by SEM, FTIR, XRD, and water contact angle assay, respectively. The porosity, degradation behavior, compressive strength, and elastic modulus of 3D porous scaffolds were also determined. To assess the scaffold bioactivity, the morphology of the deposited calcium phosphate layer on the scaffold with macro-structure was evaluated by SEM images. The viability and adhesion of MG63 osteoblast-like cells cultured on the fabricated scaffolds were examined by MTT assay and SEM images, respectively. The results show that adding GO particles not only had no effect on the interconnectivity and porosity of 3D porous macroscopic structures of neat PU but also smaller and more uniformed microscopically pores were obtained. The crystallinity, water contact angle, and weight loss of scaffolds increased as the higher GO concentrations were employed. Followed by increasing GO contents from 0 to 0.5 wt%, the compressive strength and Young’s modulus were increased by 232% and 245%, respectively. The bioactivity of scaffolds was fostered as GO concentration increased. Although, the MTT assay proved the biocompatibility of PU scaffolds containing 0.1 and 0.3 wt% GO, the samples loaded with 0.5 GO had a negative impact on the viability of MG63 cell lines. In conclusion, the present study demonstrates a high potential of PU scaffolds loaded with 0.1 and 0.3 wt% GO particles in bone tissue engineering applications.

Technical development and application of supercritical CO2 foaming technology in PCL foam production

Polycaprolactone (PCL) has the advantages of good biocompatibility, appropriate biodegradability, non-toxicity, flexibility, and processability. As a result, PCL-based foams can successfully work in bone tissue engineering, medical patches, drug delivery, reinforcing materials, and other applications. A promising technology for producing PCL foam products is supercritical CO2 (ScCO2) foaming technology, which avoids using organic solvents, is green, and has low foaming agent costs. However, due to the limitations of ScCO2 foaming technology, it is no longer possible to use this technology alone to meet current production requirements. Therefore, ScCO2 foaming technology must combine with other technologies to develop PCL foam products with better performance and matching requirements. This paper systematically reviews the technological development of ScCO2 foaming in producing PCL foams. The molding process of ScCO2 foaming and the conventional preparation process of PCL foam products are discussed comprehensively, including the preparation process, advantages, and disadvantages, challenges faced, etc. Six combined technologies for ScCO2 foaming in the production of PCL foams and the applications of PCL foams are presented. Finally, the future remaining research for producing PCL foams by ScCO2 foaming is analyzed.

Comparison of the osteogenic potential of fibroblasts from different sources

ObjectiveWith the growing interest in the role of fibroblasts in osteogenesis, this study presents a comparative evaluation of the osteogenic potential of fibroblasts derived from three distinct sources: human gingival fibroblasts (HGFs), mouse embryonic fibroblasts (NIH3T3 cells), and mouse subcutaneous fibroblasts (L929 cells). MC3T3-E1 pre-osteoblast cells were employed as a positive control for osteogenic behavior. DesignOur assessment involved multiple approaches, including vimentin staining for cell origin verification, as well as ALP and ARS staining in conjunction with RT-PCR for osteogenic characterization. ResultsOur findings revealed the superior osteogenic differentiation capacity of HGFs compared to MC3T3-E1 and NIH3T3 cells. Analysis of ALP staining confirmed that early osteogenic differentiation was most prominent in MC3T3-E1 cells at 7 days, followed by NIH3T3 and HGFs. However, ARS staining at 21 days demonstrated that HGFs produced the highest number of calcified nodules, indicating their robust potential for late-stage mineralization. This late-stage osteogenic potential of HGFs was further validated through RT-PCR analysis. In contrast, L929 cells displayed no significant osteogenic differentiation potential. ConclusionsIn light of these findings, HGFs emerge as the preferred choice for seed cells in bone tissue engineering applications. This study provides valuable insights into the potential utility of HGFs in the fields of bone tissue engineering and regenerative medicine.

A review on gold nanoparticles as an innovative therapeutic cue in bone tissue engineering: Prospects and future clinical applications

Bone damage is a complex orthopedic problem primarily caused by trauma, cancer, or bacterial infection of bone tissue. Clinical care management for bone damage remains a significant clinical challenge and there is a growing need for more advanced bone therapy options. Nanotechnology has been widely explored in the field of orthopedic therapy for the treatment of a severe bone disease. Among nanomaterials, gold nanoparticles (GNPs) along with other biomaterials are emerging as a new paradigm for treatment with excellent potential for bone tissue engineering and regenerative medicine applications. In recent years, a great deal of research has focused on demonstrating the potential for GNPs to provide for enhancement of osteogenesis, reduction of osteoclastogenesis/osteomyelitis, and treatment of bone cancer. This review details the latest understandings in regards to GNPs based therapeutic systems, mechanisms, and the applications of GNPs against various bone disorders. The present review aims to summarize i) the mechanisms of GNPs in bone tissue remodeling, ii) preparation methods of GNPs, and iii) functionalization of GNPs and its decoration on biomaterials as a delivery vehicle in a specific bone tissue engineering for future clinical application.

Osteogenic differentiation of human adipose-derived stem cells on polycaprolactone 3D-printed scaffolds containing bioactive bioceramic

Three-dimensional (3D) printing is a promising approach to fabricating bone tissue engineering scaffolds with desired geometry and properties. In this study, we hypothesized that a post-fabrication modification process with baghdadite as a bioactive glass can improve the osteoconductivity of PCL-based 3D-printed scaffolds. The main advantage of this study is the introduction of a cost-effective post-fabrication process for the treatment of 3D-printed porous scaffold for bone tissue engineering applications. The 3D-printed scaffolds were fabricated with circular four-layer and lay-down 0/90°patterns, before exposing them to three different concentrations of baghdadite (1 %, 5 %, and 10 %). The results showed that the addition of baghdadite to the PCL scaffolds did not alter the mechanical behavior of the scaffold. However, the hydrolytic degradation rate was higher for PCL/baghdadite than for plasma-treated scaffold. The biocompatibility of human adipose tissue-derived mesenchymal stem cells (hASCs) cultured on the scaffolds was evaluated by MTT and live/dead staining assays. The osteogenic differentiation ability of scaffolds was measured by evaluating alkaline phosphatase (ALP) activity, calcium deposition, and four bone-related gene expressions (osteocalcin, osteonectin, ALP, and RUNX). The results revealed that the surface treatment of printed scaffolds significantly improved the osteogenic differentiation of hASCs culture on scaffolds and therefore this method can be an effective approach for the treatment of bone tissue engineering scaffolds.