Preparation and Biocompatibility of Poly Methyl Methacrylate (PMMA)-Mesoporous Bioactive Glass (MBG) Composite Scaffolds

Investigation of Antibiotic-Releasing Biodegradable Composite Bone Cements for Treating Experimental Chronic Maxillofacial Bone Infection

Chronic osteomyelitis of the maxillofacial bones (i.e., jaw bones) is a persistent infection that requires effective treatment. Because systemic antibiotics seldom reach necrotic areas to remove bone infection, local antibiotic carriers such as antibiotic-loaded bone cement can be tried. It is critical to assess the biosafety and efficacy of two new antibiotic-loaded biodegradable composite bone cements for treating chronic mandibular osteomyelitis, and their drug eluting efficiency and other relevant aspects prior to clinical trial. The physico-mechanical properties, and drug release capacity of the cements were determined to be suitable for in vivo application. After inducing chronic osteomyelitis with Staphylococcal strains in 30 female rabbit mandibles, bioactive glass composite cement (0.5 g) and biphasic calcium phosphate composite cement (0.5 g) were implanted in 18 defects (nine/test group) for 84 days to compare the therapeutic efficacy with traditional therapy (control, debridement plus antibiotics in nine defects) using microscopic, micrographic, and radiological examination. Antibiotic concentrations in bone (vancomycin: 34.7-53.2 μg/g, tobramycin: 2.1-2.87 μg/g) after 21 days of installation for both cements were sufficient to eradicate pathogens without causing adverse events. In vivo tests suggest that cement groups outperformed (p < 0.05) traditional therapy in terms of infection clearance and osteoconduction. The gross histologic and micrographic scores of biphasic calcium phosphate composite cement (10.33 ± 0.58 and 8.33 ± 1.53, respectively) indicated that the cement barely surpassed (p > 0.05) the other composite cement (12.67 ± 1.53 and 10.0 ± 1.0, respectively). These findings emphasize the potential of antibiotic loaded composite cements as an effective treatment option for chronic maxillofacial osteomyelitis, offering a safer and more efficient alternative to traditional therapy.

Bioinspired 3D scaffolds with antimicrobial, drug delivery, and osteogenic functions for bone regeneration

A major clinical challenge today is the large number of bone defects caused by diseases or trauma. The development of three-dimensional (3D) scaffolds with adequate properties is crucial for successful bone repair. In this study, we prepared biomimetic mesoporous bioactive glass (MBG)-based scaffolds with and without ceria addition (up to 3 mol %) to explore the biological structure and chemical composition of the marine sponge Spongia Agaricina (SA) as a sacrificial template. Micro-CT examination revealed that all scaffolds exhibited a highly porous structure with pore diameters primarily ranging from 143.5 μm to 213.5 μm, facilitating bone ingrowth. Additionally, smaller pores (< 75 μm), which are known to enhance osteogenesis, were observed. The undoped scaffold displayed the highest open porosity value of 90.83%. Cytotoxicity assessments demonstrated that all scaffolds were noncytotoxic and nongenotoxic toward osteoblast cells. Moreover, scaffolds with higher CeO2 content promoted osteogenic differentiation of dental pulp stem cells, stimulating calcium and osteocalcin secretion. The scaffolds also exhibited antimicrobial and antibiofilm effects against Staphylococcus aureus (S. aureus) as well as drug delivery ability. Our research findings indicated that the combination of MBG, natural biological structure, and the addition of Ce exhibited a synergistic effect on the structure and biological properties of scaffolds for applications in bone tissue engineering.

Engineering mesoporous bioactive glasses for emerging stimuli-responsive drug delivery and theranostic applications

Mesoporous bioactive glasses (MBGs), which belong to the category of modern porous nanomaterials, have garnered significant attention due to their impressive biological activities, appealing physicochemical properties, and desirable morphological features. They hold immense potential for utilization in diverse fields, including adsorption, separation, catalysis, bioengineering, and medicine. Despite possessing interior porous structures, excellent morphological characteristics, and superior biocompatibility, primitive MBGs face challenges related to weak encapsulation efficiency, drug loading, and mechanical strength when applied in biomedical fields. It is important to note that the advantageous attributes of MBGs can be effectively preserved by incorporating supramolecular assemblies, miscellaneous metal species, and their conjugates into the material surfaces or intrinsic mesoporous networks. The innovative advancements in these modified colloidal inorganic nanocarriers inspire researchers to explore novel applications, such as stimuli-responsive drug delivery, with exceptional in-vivo performances. In view of the above, we outline the fabrication process of calcium-silicon-phosphorus based MBGs, followed by discussions on their significant progress in various engineered strategies involving surface functionalization, nanostructures, and network modification. Furthermore, we emphasize the recent advancements in the textural and physicochemical properties of MBGs, along with their theranostic potentials in multiple cancerous and non-cancerous diseases. Lastly, we recapitulate compelling viewpoints, with specific considerations given from bench to bedside.

Synthesis of bioactive heat cured PMMA/PEKK blend reinforced by nano titanium dioxide for bone scaffold applications

In bone tissue engineering (BTE), defects in large bones remain the greatest issue which can be addressed using bone scaffolds. In this work, blends of heat cured polymethylmethacrylate (HC PMMA) and various weight percentages of poly-ether-ketone-ketone (PEKK) (0, 2, 4, 8, and 10%) were made using a porogen leaching process. The blends were then subjected to tensile, compression and bending tests to select the optimum blend. Based on the results obtained, HC PMMA blended with 2 wt% PEKK was selected to produce the bio-porous blends. Here, the porosity was imparted using tartaric acid (C4H6O6) and sodium hydrogen carbonate (NaHCO3) as porogen leaching components. Porous blends resulted were then reinforced with a nano titanium dioxide powder (nTiO2) at different weight percentages of (0, 1, 3, and 5). The results showed that porous composites made of (HC PMMA: 2 wt% PEKK) blend reinforced with 5 wt % nTiO2 exhibit the highest strength values under various loadings. The FTIR identified the functional groups of the bone scaffold components. The mean pore size and pore depth were measured using atomic force microscopy (AFM) analysis and the values are 92.6 nm and 42.78 nm, respectively. The good distribution of the PEKK and nTiO2 within the HC PMMA and the uniform porous structure with multi-scale pores between 535 nm and 1.187 mm were confirmed by the AFM data and SEM images, respectively. This research expected that the porous composite (HC PMMA: 2% PEKK: 5% nTiO2) is a good candidate for bone scaffold applications.

3D interconnected porous PMMA scaffold integrating with advanced nanostructured CaP-based biomaterials for rapid bone repair and regeneration

Bioactive scaffolds with polymer and nanostructured bioactive glass-based composites are promising materials for regenerative applications in consequence of close mimics of natural bone composition. Poly methyl methacrylate (PMMA) is a highly preferred thermoplastic polymer for orthopedic applications as it has good biocompatibility. Different kinds of bioactive, biodegradable as well as biocompatible biomaterial composites such as Bioglass (BG), Hydroxyapatite (Hap), and Tricalcium phosphate (TCP) can be integrated with PMMA, so as to augment the bioactivity, porosity as well as regeneration of hard tissues in human body. Among the bioactive glass, 60S BG (Bioactive glass with 60 percentage of Silica without Sodium ions) is better materials among aforementioned systems owning to mechanical stability as well as controlled bioactive material. In this work, the fabrication of PMMA-CaP (calcium phosphate)-based scaffolds were carried out by Thermal Induced Phase Separation method (TIPS). X-ray diffractogram analysis (XRD) is used to examine the physiochemical properties of the scaffolds that evidently reveal the presence of calcium phosphate besides calcium phosphate silicate phases. The Field Emission Scanning Electron Microscopy (FESEM) studies obviously exhibited the microstructure of the scaffolds as well as their interconnected porous morphology. The PMMA/60S BG/TCP (C50) scaffold has the maximum pore size, measuring 77 ± 23 μm, while the average pore size ranges from 50 ± 20 to 80 ± 23 μm. By performing a liquid displacement method, the C50 scaffold is found to have the largest porosity of 50%, high hydrophilicity of 118.16°, and a compression test reveals the scaffolds to have a maximum compressive strength of 0.16 MPa. The emergence of bone-like apatite on the scaffold surface after 1st and 21st days of SBF immersion is further supported by in vitro bioactivity studies. Cytocompatibility and hemocompatibility analyses undoubtedly confirmed the biocompatibility behavior of PMMA-based bioactive scaffolds. Nano-CT investigation demonstrates that PMMA-CaP scaffolds provide more or less alike morphologies of composites that resemble the natural bone. Therefore, this combination of scaffolds could be considered as potential biomaterials for bone regeneration application. This detailed study promisingly demonstrates the eminence of the unique scaffolds in the direction of regenerative medicines.

Special Issue: Bioceramics, Bioglasses, and Gels for Tissue Engineering

Undoubtedly, biomaterials such as bioceramics, bioactive glasses, and gels have attracted a wide range of research interest in the field of tissue engineering (TE), as they facilitate the essential support and environment for cells to grow, differentiate, and, specifically, regenerate new tissues [...].

Chitosan scaffolds with mesoporous hydroxyapatite and mesoporous bioactive glass

Bone regeneration is one of the most well-known fields in tissue regeneration. The major focus concerns polymeric/ceramic composite scaffolds. In this work, several composite scaffolds based on chitosan (CH), with low and high molecular weights, and different concentrations of ceramics like mesoporous bioactive glass (MBG), mesoporous hydroxyapatite (MHAp) and both MBG and MHAp (MC) were produced by lyophilization. The purpose is to identify the best combination regarding optimal morphology and properties. The tests of the scaffolds present a highly porous structure with interconnected pores. The compression modulus increases with ceramic concentration in the scaffolds. Furthermore, the 75%MBG (835 ± 160 kPa) and 50%MC (1070 ± 205 kPa) samples are the ones that mostly enhance increases in mechanical properties. The swelling capacity increases with MBG and MC, respectively, to 700% and 900% and decreases to 400% when MHAp concentration increases. All scaffolds are non-cytotoxic at 12.5 mg/mL. The CHL scaffolds improve cell adhesion and proliferation compared to CHH, and the MC scaffold samples, show better results than those produced with just MBG or MHAp. The composite scaffolds of chitosan with MBG and MHAp, have revealed to be the best combination due to their enhanced performance in bone tissue engineering.

Cerium-Containing Mesoporous Bioactive Glasses (MBGs)-Derived Scaffolds with Drug Delivery Capability for Potential Tissue Engineering Applications

Finding innovative solutions to improve the lives of people affected by trauma, bone disease, or aging continues to be a challenge worldwide. Tissue engineering is the most rapidly growing area in the domain of biomaterials. Cerium-containing MBG-derived biomaterials scaffolds were synthesized using polymethyl methacrylate (PMMA) as a sacrificial template. The obtained scaffolds were characterized by X-ray powder diffraction (XRPD), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The Ce4+/Ce3+ ratio in the scaffolds was estimated. In vitro testing revealed good cytocompatibility of the investigated scaffolds in mouse fibroblast cell line (NCTC clone L929). The results obtained regarding bioactivity, antibacterial activity, and controlled drug delivery functions recommend these scaffolds as potential candidates for bone tissue engineering applications.