Implantable Biomaterials Research Articles

Challenges and Pitfalls of Research Designs Involving Magnesium-Based Biomaterials: An Overview.

Magnesium-based biomaterials hold remarkable promise for various clinical applications, offering advantages such as reduced stress-shielding and enhanced bone strengthening and vascular remodeling compared to traditional materials. However, ensuring the quality of preclinical research is crucial for the development of these implants. To achieve implant success, an understanding of the cellular responses post-implantation, proper model selection, and good study design are crucial. There are several challenges to reaching a safe and effective translation of laboratory findings into clinical practice. The utilization of Mg-based biomedical devices eliminates the need for biomaterial removal surgery post-healing and mitigates adverse effects associated with permanent biomaterial implantation. However, the high corrosion rate of Mg-based implants poses challenges such as unexpected degradation, structural failure, hydrogen evolution, alkalization, and cytotoxicity. The biocompatibility and degradability of materials based on magnesium have been studied by many researchers in vitro; however, evaluations addressing the impact of the material in vivo still need to be improved. Several animal models, including rats, rabbits, dogs, and pigs, have been explored to assess the potential of magnesium-based materials. Moreover, strategies such as alloying and coating have been identified to enhance the degradation rate of magnesium-based materials in vivo to transform these challenges into opportunities. This review aims to explore the utilization of Mg implants across various biomedical applications within cellular (in vitro) and animal (in vivo) models.

Device Design and Advanced Computed Tomography of 3D Printed Radiopaque Composite Scaffolds and Meniscus

Abstract3D‐printed biomaterial implants are revolutionizing personalized medicine for tissue repair, especially in orthopedics. In this study, a radiopaque bismuth oxide (Bi2O3) doped polycaprolactone (PCL) composite is developed and implemented to enable the use of diagnostic X‐ray technologies, especially spectral photon counting X‐ray computed tomography (SPCCT), for comprehensive tissue engineering scaffold (TES) monitoring. PCL filament with homogeneous Bi2O3 nanoparticle (NP) dispersion (0.8 to 11.7 wt%) is first fabricated. TES are then 3D printed with the composite filament, optimizing printing parameters for small features and severely overhung geometries. These composite TES are characterized via micro‐computed tomography (µCT), tensile testing, and a cytocompatibility study, with 2 wt% Bi2O3 NPs providing improved tensile properties, equivalent cytocompatibility to neat PCL, and excellent radiographic distinguishability. Radiographic performance is validated in situ by imaging 4 and 7 wt% Bi2O3 doped PCL TES in a mouse model with µCT, showing excellent agreement with in vitro measurements. Subsequently, CT image‐derived swine menisci are 3D printed with composite filament and re‐implanted in corresponding swine legs ex vivo. Re‐imaging the swine legs via clinical CT allows facile identification of device location and alignment. Finally, the emergent technology of SPCCT unambiguously distinguishes the implanted meniscus in situ via color K‐edge imaging.

Immunoengineering Biomaterials for Musculoskeletal Tissue Repair across Lifespan.

Musculoskeletal diseases and injuries are among the leading causes of pain and morbidity worldwide. Broad efforts have focused on developing pro-regenerative biomaterials to treat musculoskeletal conditions; however, these approaches have yet to make a significant clinical impact. Recent studies have demonstrated that the immune system is central in orchestrating tissue repair and that targeting pro-regenerative immune responses can improve biomaterial therapeutic outcomes. However, aging is a critical factor negatively affecting musculoskeletal tissue repair and immune function. Hence, understanding how age affects the response to biomaterials is essential for improving musculoskeletal biomaterial therapies. This review focuses on the intersection of the immune system and aging in response to biomaterials for musculoskeletal tissue repair. The article introduces the general impacts of aging on tissue physiology, the immune system, and the response to biomaterials. Then, it explains how the adaptive immune system guides the response to injury and biomaterial implants in cartilage, muscle, and bone and discusses how aging impacts these processes in each tissue type. The review concludes by highlighting future directions for the development and translation of personalized immunomodulatory biomaterials for musculoskeletal tissue repair.

Use of allograft bone matrix in clinical orthopedics.

Clinical orthopedics continuously aims to improve methods for bone formation. Clinical applications where bone formation is necessary include critical long bone defects in orthopedic trauma or tumor patients. Though some biomaterials combined with autologous stem cells significantly improve bone repair, critical-size damages are still challenged with the suitable implantation of biomaterials and donor cell survival. Extracellular matrix (ECM) is the fundamental structure in tissues that can nest and nourish resident cells as well as support specific functions of the tissue type. ECM also plays a role in cell signaling to promote bone growth, healing and turnover. In the last decade, the use of bone-derived ECMs or ECM-similar biomaterials have been widely investigated, including decellularized and demineralized bone ECM. In this article, we reviewed the current productions and applications of decellularized and demineralized bone matrices. We also introduce the current study of whole limb decellularization and recellularization.

A Preclinical Trial Protocol Using an Ovine Model to Assess Scaffold Implant Biomaterials for Repair of Critical-Sized Mandibular Defects.

The present work describes a preclinical trial (in silico, in vivo and in vitro) protocol to assess the biomechanical performance and osteogenic capability of 3D-printed polymeric scaffolds implants used to repair partial defects in a sheep mandible. The protocol spans multiple steps of the medical device development pipeline, including initial concept design of the scaffold implant, digital twin in silico finite element modeling, manufacturing of the device prototype, in vivo device implantation, and in vitro laboratory mechanical testing. First, a patient-specific one-body scaffold implant used for reconstructing a critical-sized defect along the lower border of the sheep mandible ramus was designed using on computed-tomographic (CT) imagery and computer-aided design software. Next, the biomechanical performance of the implant was predicted numerically by simulating physiological load conditions in a digital twin in silico finite element model of the sheep mandible. This allowed for possible redesigning of the implant prior to commencing in vivo experimentation. Then, two types of polymeric biomaterials were used to manufacture the mandibular scaffold implants: poly ether ether ketone (PEEK) and poly ether ketone (PEK) printed with fused deposition modeling (FDM) and selective laser sintering (SLS), respectively. Then, after being implanted for 13 weeks in vivo, the implant and surrounding bone tissue was harvested and microCT scanned to visualize and quantify neo-tissue formation in the porous space of the scaffold. Finally, the implant and local bone tissue was assessed by in vitro laboratory mechanical testing to quantify the osteointegration. The protocol consists of six component procedures: (i) scaffold design and finite element analysis to predict its biomechanical response, (ii) scaffold fabrication with FDM and SLS 3D printing, (iii) surface treatment of the scaffold with plasma immersion ion implantation (PIII) techniques, (iv) ovine mandibular implantation, (v) postoperative sheep recovery, euthanasia, and harvesting of the scaffold and surrounding host bone, microCT scanning, and (vi) in vitro laboratory mechanical tests of the harvested scaffolds. The results of microCT imagery and 3-point mechanical bend testing demonstrate that PIII-SLS-PEK is a promising biomaterial for the manufacturing of scaffold implants to enhance the bone-scaffold contact and bone ingrowth in porous scaffold implants. MicroCT images of the harvested implant and surrounding bone tissue showed encouraging new bone growth at the scaffold-bone interface and inside the porous network of the lattice structure of the SLS-PEK scaffolds.

Mir-146a is required for foreign body response and giant cell formation

The implantation of biomaterials or medical devices often leads to the development of a foreign body response (FBR), an inflammatory condition that can lead to implant failure, which may cause harm to or death of the patient. Hallmarks of the FBR include accumulation of macrophages and destructive foreign body giant cells (FBGCs), and development of fibrous scar tissue encompassing the implant. There are no effective medical treatments for FBR, although improved fundamental understanding of the molecular mechanisms underlying the development of FBR may lead to novel strategies for the amelioration of FBR. MicroRNAs (miRs) are endogenous, small, non-coding RNAs that have emerged as powerful regulators of gene expression in numerous cellular processes including macrophage activation, inflammation, and fibrosis. In this research, we tested the hypothesis that specific miRs play a crucial role in regulating the FBR to biomaterials. In our subcutaneous implantation mouse model, we found that: 1) miR-146a expression levels decreased in the implant-adhered tissues, and the decrease correlated with increased macrophage accumulation, FBGC formation, and collagen accumulation; and 2) miR-146a deletion in mice exacerbated in vivo macrophage accumulation, FBGC formation, and collagen accumulation. In our in vitro model, we found that deficiency of miR-146a function exacerbated key macrophage functions including adhesion on stiff matrix, and FBGC formation in primary mouse macrophages. In essence, our findings suggest that miR-146a might act as a suppressor of FBR. We expect that the results of this study may provide invaluable information and insight regarding the molecular mechanisms mediating the FBR to biomaterials, which may lead to the development of a novel microRNA-based therapeutic strategy for the amelioration of the poorly understood FBR to biomaterials. NIH (R01 AI172086) grant to Shaik O. Rahaman. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Cytotoxicity, Corrosion Resistance, and Wettability of Titanium and Ti-TiB2 Composite Fabricated by Powder Metallurgy for Dental Implants

Objectives: Orthopedics and dentistry have widely utilized titanium alloys as biomaterials for dental implants, but limited research has been conducted on the fabrication of ceramic particle-reinforced Ti composites for further weight reductions. The current study compared titanium–titanium diboride metal composites (Ti-TiB2) with pure titanium (processed by powder metallurgy) in terms of toxicity, corrosion resistance, and wettability. Methods: First, cell lines of a primary dermal fibroblast normal human adult (HDFa) were used to test the cytocompatibility (in vitro) of the composite and pure Ti using an indirect contact approach. Corrosion testing was performed for the materials using electrochemical techniques such as potentiodynamic polarization in a simulated bodily fluid (SBF) in conjunction with a three-electrode electrochemical cell. The entire set of experimental tests was conducted according to the ASTM F746-04 protocol. The contact angles were measured during wettability testing in accordance with ASTM D7334-08. An X-ray diffractometer (XRD) was used to catalog every phase that was visible in the microstructure. A scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to determine the chemical composition. Results: The cytotoxicity tests revealed that there was no detectable level of toxicity, and there was no significant difference in the impact of either of the two materials on the viability of human fibroblasts. An increase in the corrosion resistance of the composite (0.036 ± 0.0001 mpy (millimeters per year)) demonstrated the development of a passive oxide coating. According to the findings, the composites showed a greater degree of hydrophilicity (contact angle 44.29° ± 0.28) than did the pure titanium (56.31° ± 0.47). Conclusions/Significance: The Ti-TiB2 composite showed no toxicity and better corrosion resistance and wettability than did pure Ti. The composite could be a suitable alternative to Ti for applications involving dental implants.

Advancement in ceramic biomaterials for dental implants

AbstractThere has been enormous research on diagnostic and therapeutic dental methods due to the growing recognition of oral wellness. Numerous studies in this area have resulted in dental biomaterials, including polymers, metals, and acrylic resins, essential to restore teeth affected by illnesses or accidents. Compared to other biomaterials, such as metals or polymers, ceramics offer distinct features. Materials like zirconia and alumina demonstrate their high intrinsic strength, making them appropriate for biomedical applications like dental implants or artificial joints. Additionally, they have outstanding biocompatibility, which lowers the possibility of adverse effects or inflammation. Some ceramics, like hydroxyapatite (HA) and bioactive glasses, even encourage tissue integration and regeneration. Moreover, because of their adaptability, they can be precisely shaped and composed to emphasize specific characteristics. Yttria‐stabilized tetragonal zirconia offers outstanding mechanical properties and biocompatibility but faces concerns over long‐term durability due to low‐temperature degradation. To address this, researchers have developed non‐oxidic ceramics like silicon nitride and advanced oxide‐based materials like alumina‐zirconia composites, aiming to enhance the durability and reliability of biomedical applications. In this review, we highlighted the recent advancements in ceramic dental implants; examples and applications of different ceramics‐based materials, including zirconia, alumina, HA, and beta calcium phosphate, are provided in detail.

Relationship between ceramic additives and improved biodegradability, osseointegration, and surface roughness of Ni–Ti shape memory alloy for use in load-bearing bone site applications

To make metallic biomaterial implants acceptable for use in bone replacement applications, this research aimed to identify a potential means of improving the poor wear resistance of implants as well as their limited osseointegration capability and rapid biodegradation. In this regard, mechanical alloying was used to make a nickel-titanium (Ni–Ti) shape memory alloy with increasing amounts of hardystonite (HT) and niobium carbide (NbC). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to examine the phase composition and microstructure of the sintered samples. To test osseointegration and biodegradation, samples were immersed in simulated body fluid (SBF). They were then analyzed using SEM, weight loss measurements, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The SEM pictures indicated that increasing HT and NbC helped build apatite layers on their surfaces, anticipating successful osseointegration if utilized as bone implants. ICP findings showed that HT and NbC significantly reduced Ni2+ ion release, preventing tissue damage. In contrast to electrical conductivity, these ceramics improved the compressive strength and microhardness of the examined samples. The improvement in their strength was 10.81, 27.02, 21.62, and 31.89 %. SEM results confirmed the role of ceramic materials to enhance the wear resistance of the tested samples. Based on these findings, the prepared nanocomposites achieved the main goal of this study.

Human T-Cell Responses to Metallic Ion-Doped Bioactive Glasses.

Biomaterials are extensively used as replacements for damaged tissue with bioactive glasses standing out as bone substitutes for their intrinsic osteogenic properties. However, biomaterial implantation has the following risks: the development of implant-associated infections and adverse immune responses. Thus, incorporating metallic ions with known antimicrobial properties can prevent infection, but should also modulate the immune response. Therefore, we selected silver, copper and tellurium as doping for bioactive glasses and evaluated the immunophenotype and cytokine profile of human T-cells cultured on top of these discs. Results showed that silver significantly decreased cell viability, copper increased the T helper (Th)-1 cell percentage while decreasing that of Th17, while tellurium did not affect either cell viability or immune response, as evaluated via multiparametric flow cytometry. Multiplex cytokines assay showed that IL-5 levels were decreased in the copper-doped discs, compared with its undoped control, while IL-10 tended to be lower in the doped glass, compared with the control (plastic) while undoped condition showed lower expression of IL-13 and increased MCP-1 and MIP-1β secretion. Overall, we hypothesized that the Th1/Th17 shift, and specific cytokine expression indicated that T-cells might cross-activate other cell types, potentially macrophages and eosinophils, in response to the scaffolds.

Immunomodulation Using BMP-7 and IL-10 to Enhance the Mineralization Capacity of Bone Progenitor Cells in a Fracture Hematoma-Like Environment.

Following biomaterial implantation, a failure to resolve inflammation during the formation of a fracture hematoma can significantly limit the biomaterial's ability to facilitate bone regeneration. This study aims to combine the immunomodulatory and osteogenic effects of BMP-7 and IL-10 with the regenerative capacity of collagen-hydroxyapatite (CHA) scaffolds to enhance in vitro mineralization in a hematoma-like environment. Incubation of CHA scaffolds with human whole blood leads to rapid adsorption of fibrinogen, significant stiffening of the scaffold, and the formation of a hematoma-like environment characterized by a limited capacity to support the infiltration of human bone progenitor cells, a significant upregulation of inflammatory cytokines and acute phase proteins, and significantly reduced osteoconductivity. CHA scaffolds functionalized with BMP-7 and IL-10 significantly downregulate the production of key inflammatory cytokines, including IL-6, IL-8, and leptin, creating a more permissive environment for mineralization, ultimately enhancing the biomaterial's osteoconductivity. In conclusion, targeting the onset of inflammation in the early phase of bone healing using BMP-7 and IL-10 functionalized CHA scaffolds is a promising approach to effectively downregulate inflammatory processes, while fostering a more permissive environment for bone regeneration.

Biodegradable SPI-based hydrogel for controlled release of nanomedicines: A potential approach against brain tumors recurrence

Glioblastoma (GB) is the most common and aggressive brain tumor. The treatment for newly diagnosed glioblastoma is surgical resection of the primary tumor mass, followed by radiotherapy and chemotherapy. However, recurrences frequently occur in proximity to the surgical resection area. In these cases, none of the current therapies is effective. Recently, implantable biomaterials seem to be a promising strategy against GB recurrence. Here, for the first time we combined the tailorable properties of soy-protein hydrogels with the versatility of drug-loaded liposomes to realize a hybrid biomaterial for controlled and sustained nanoparticles release. Hydrogel consisting of 18–20 % w/v soy-protein isolated were fabricated in absence of chemical cross-linkers. They were biodegradable (−10 % and −30 % of weight by hydrolytic and enzymatic degradation, respectively in 3 days), biocompatible (>95 % of cell viability after treatment), and capable of sustained release of intact doxorubicin-loaded liposomes (diffusion coefficient between 10−18 and 10 −19 m2 s−1). A proof-of-concept in a “donut-like” 3D-bioprinted model shows that liposomes released by hydrogels were able to diffuse in a model with a complex extracellular matrix-like network and a 3D structural organization, targeting glioblastoma cells.The combination of nanoparticles' encapsulation capabilities with the hydrogels' structural support and controlled release properties will provide a powerful tool with high clinical relevance that could be applicable for the treatment of other cancers, realizing patient-specific interventions.

Ti-Zr alloy (ROXOLID) will become a Paradigm Shift in Implant Material? -A Narrative Review

Titanium and Zirconia are one of the most widely used biomaterials for dental implants. Titanium has an excellent osseointegration but has insufficient mechanical resistance and the zirconia implants are used in anterior regions. So, TiZr alloy( Roxolid) was introduced that increased mechanical resistance than titanium alloys with similar biocompatibility to bone tissues. In this narrative review, the authors discuss various properties of TiZr alloy and use of these as implant materials due to their superior properties. Keywords: Titanium, Zirconia, TiZr alloy, Roxolid, Implant material.

Mgp High-Expressing MSCs Orchestrate the Osteoimmune Microenvironment of Collagen/Nanohydroxyapatite-Mediated Bone Regeneration.

Activating autologous stem cells after the implantation of biomaterials is an important process to initiate bone regeneration. Although several studies have demonstrated the mechanism of biomaterial-mediated bone regeneration, a comprehensive single-cell level transcriptomic map revealing the influence of biomaterials on regulating the temporal and spatial expression patterns of mesenchymal stem cells (MSCs) is still lacking. Herein, the osteoimmune microenvironment is depicted around the classical collagen/nanohydroxyapatite-based bone repair materials via combining analysis of single-cell RNA sequencing and spatial transcriptomics. A group of functional MSCs with high expression of matrix Gla protein (Mgp) is identified, which may serve as a pioneer subpopulation involved in bone repair. Remarkably, these Mgp high-expressing MSCs (MgphiMSCs) exhibit efficient osteogenic differentiation potential and orchestrate the osteoimmune microenvironment around implanted biomaterials, rewiring the polarization and osteoclastic differentiation of macrophages through the Mdk/Lrp1 ligand-receptor pair. The inhibition of Mdk/Lrp1 activates the pro-inflammatory programs of macrophages and osteoclastogenesis. Meanwhile, multiple immune-cell subsets also exhibit close crosstalk between MgphiMSCs via the secreted phosphoprotein 1 (SPP1) signaling pathway. These cellular profiles and interactions characterized in this study can broaden the understanding of the functional MSC subpopulations at the early stage of biomaterial-mediated bone regeneration and provide the basis for materials-designed strategies that target osteoimmune modulation.

Synergistic effects of graphene microgrooves and electrical stimulation on M2 macrophage polarization

Macrophages play a crucial role in host response and wound healing, with M2 polarization contributing to the reduction of foreign-body reactions induced by the implantation of biomaterials and promoting tissue regeneration. Electrical stimulation (ES) and micropatterned substrates have a significant impact on the macrophage polarization. However, there is currently a lack of well-established cell culture platforms for studying the synergistic effects of these two factors. In this study, we prepared a graphene free-standing substrate with 20 μm microgrooves using capillary forces induced by water evaporation. Subsequently, we established an ES cell culture platform for macrophage cultivation by integrating a self-designed multi-well chamber cell culture device. We observed that graphene microgrooves, in combination with ES, significantly reduce cell spreading area and circularity. Results from immunofluorescence, ELISA, and flow cytometry demonstrate that the synergistic effect of graphene microgrooves and ES effectively promotes macrophage M2 phenotypic polarization. Finally, RNA sequencing results reveal that the synergistic effects of ES and graphene microgrooves inhibit the macrophage actin polymerization and the downstream PI3K signaling pathway, thereby influencing the phenotypic transition. Our results demonstrate the potential of graphene-based microgrooves and ES to synergistically modulate macrophage polarization, offering promising applications in regenerative medicine.

Comparison of 3D-printed poly-ether-ether-ketone and traditional implant materials in cranioplasty

The advancement in material science and processing methods has led to the continuous development of novel biomaterial implants and bone flap manufacturing methods in cranioplasty. This retrospective study aimed to investigate the outcomes and clinical prognosis of patients undergoing skull repair using fused filament fabrication (FFF)-printed poly-ether-ether-ketone (PEEK) implants versus traditional implants (i.e., autologous bone and titanium mesh). We recruited patients who underwent cranioplasty (performed by senior surgeons) between January 2021 and March 2023. A total of 66 patients who underwent cranioplasty were included in this study and divided into three groups according to the material used for their respective implants: (i) three-dimensional (3D)-printed PEEK, (ii) autologous bone, and (iii) titanium mesh. Infection, epilepsy, and transplant failure did not occur in any of the three groups. Additionally, there were no statistically significant differences in terms of implant-related complications and patient neurological function among the three groups 6 months after discharge (P > 0.05). This study demonstrated the feasibility, safety, and aesthetics of 3D-printed PEEK implants for clinical application. Nonetheless, 3D printing may be a promising translational technology for the future of neurosurgery.

Effect of tunable stiffness on immune responses in 3D-bioprinted alginate–gelatin scaffolds

Tissue engineering is an approach used to restore damaged tissues and organs using biomaterials that support cell adhesion, growth, and proliferation. However, immune responses triggered by tissue injury and biomaterial implantation can lead to undesired reactions such as foreign body response and fibrotic capsule formation. Macrophages play a critical role in these immune responses. Therefore, comprehending and controlling the immune responses to biomaterials are crucial for successful clinical translation in tissue engineering. In this experimental study, we fabricated three-dimensional-bioprinted hydrogel scaffolds with adaptable stiffness by adjusting the alginate–gelatin ratio. We examined the physical properties of these scaffolds and assessed the immune responses they provoked both in vitro and in vivo. Our results revealed that higher-stiffness implants could drive macrophage polarization toward pro-inflammatory phenotypes in vivo. Furthermore, our animal experiments demonstrated that high-stiffness hydrogels elicited elevated immune responses through the TLR4/Myd88/NF-κB signaling pathway and IL-6/JAK-STAT signaling pathway. Collectively, our study demonstrates that increased implant stiffness correlates with stronger immune responses. These findings are expected to provide novel insights for the clinical application of alginate–gelatin composite hydrogels.

CD4+ and CD8+ T cells reduce inflammation and promote bone healing in response to titanium implants

T cells are adaptive immune cells essential in pathogenic response, cancer, and autoimmune disorders. During the integration of biomaterials with host tissue, T cells modify the local inflammatory environment by releasing cytokines that promote inflammatory resolution following implantation. T cells are vital for the modulation of innate immune cells, recruitment and proliferation of mesenchymal stem cells (MSCs), and formation of functional tissue around the biomaterial implant. We have demonstrated that deficiency of αβ T cells promotes macrophage polarization towards a pro-inflammatory phenotype and attenuates MSC recruitment and proliferation in vitro and in vivo. The goal of this study was to understand how CD4+ and CD8+ T cells, subsets of the αβ T cell family, impact the inflammatory response to titanium (Ti) biomaterials. Deficiency of either CD4+ or CD8+ T cells increased the proportion of pro-inflammatory macrophages, lowered anti-inflammatory macrophages, and diminished MSC recruitment in vitro and in vivo. In addition, new bone formation at the implantation site was significantly reduced in T cell-deficient mice compared to T cell-competent mice. Deficiency of CD4+ T cells exacerbated these effects compared to CD8+ T cell deficiency. Our results show the importance of CD4+ and CD8+ T cells in modulating the inflammatory response and promoting new bone formation in response to modified Ti implants. Statement of significanceCD4+ and CD8+ T cells are essential in modulating the peri-implant microenvironment during the inflammatory response to biomaterial implantation. This study shows that deficiency of either CD4+ or CD8+ T cell subsets altered macrophage polarization and reduced MSC recruitment and proliferation at the implantation site.

An Overview on the Big Players in Bone Tissue Engineering: Biomaterials, Scaffolds and Cells.

Presently, millions worldwide suffer from degenerative and inflammatory bone and joint issues, comprising roughly half of chronic ailments in those over 50, leading to prolonged discomfort and physical limitations. These conditions become more prevalent with age and lifestyle factors, escalating due to the growing elderly populace. Addressing these challenges often entails surgical interventions utilizing implants or bone grafts, though these treatments may entail complications such as pain and tissue death at donor sites for grafts, along with immune rejection. To surmount these challenges, tissue engineering has emerged as a promising avenue for bone injury repair and reconstruction. It involves the use of different biomaterials and the development of three-dimensional porous matrices and scaffolds, alongside osteoprogenitor cells and growth factors to stimulate natural tissue regeneration. This review compiles methodologies that can be used to develop biomaterials that are important in bone tissue replacement and regeneration. Biomaterials for orthopedic implants, several scaffold types and production methods, as well as techniques to assess biomaterials' suitability for human use-both in laboratory settings and within living organisms-are discussed. Even though researchers have had some success, there is still room for improvements in their processing techniques, especially the ones that make scaffolds mechanically stronger without weakening their biological characteristics. Bone tissue engineering is therefore a promising area due to the rise in bone-related injuries.

Pelvic Organ Prolapse Reconstruction with the Chitosan-Based Novel Haemostatic Agent in Ovine Model-Preliminary Report.

This prospective study aimed to assess the feasibility of chitosan biomaterial and subcutaneous gel implantation in an ovine model, with implications for women with genital prolapse. Twenty-four ewes were divided into four groups (n = 6 per group): chitosan type B, chitosan type C, chitosan unmodified injections, and polypropylene mesh. Ovine models were chosen due to their morphological resemblance to human reproductive organs. Animals were sacrificed after 90 days for macroscopic, pathomorphological, and immunohistochemical analysis. In the chitosan type B group, IL-6 and IL-10 levels decreased after 28 days, while chitosan type C and injection groups exhibited higher IL-6 than IL-10 levels. The polypropylene group displayed the highest IL-6 and lowest IL-10 levels. Histological examination of the polypropylene group revealed no degenerative changes or inflammation, whereas chitosan injection induced local inflammation. Other groups exhibited no degenerative changes. Ewes implanted with chitosan displayed reduced inflammation compared to polypropylene-implanted ewes. Chitosan implantation facilitated vaginal tissue healing, in contrast to polypropylene mesh, which led to extrusion. While chitosan holds promise as an alternative to polypropylene mesh, further research is imperative for comprehensive evaluation. This study suggests the potential of a chitosan biomaterial in pelvic organ prolapse treatment, warranting additional investigation.