A Bioinspired Gelatin-Amorphous Calcium Phosphate Coating on Titanium Implant for Bone Regeneration

Injectable and drug-loaded gelatin methacrylate and carboxymethylated-sulfated xanthan gum hydrogels as biomimetic mineralization constructs

Injectable and drug-loaded hydrogels based on gelatin and xanthan gum derivatives were biomineralized to form organic-inorganic hybrid composites with osteoconductivity and controllable release of antibiotic drug for inducing bone generation. Gelatin was amidated to get gelatin methacrylate (GM) for supporting cell adhesion and photo-crosslinkability. Xanthan gum was chemically modified to obtain carboxymethalated and sulfated derivatives (CMXG and SXG) with high negative charges for mimicking chondroitin sulfate in bone. GM was co-dissolved with CMXG/SXG and ciprofloxacin hydrochloride (CPFXH), and photo-crosslinked with lithium phenyl-2,4,6-tri methylbenzoylphosphinate (LAP) to fabricate drug-loaded CMXG/SXG-GM-CPFXH-LAP hydrogels, which possessed swelling ratio of 1.30 ± 0.03 and controlled release of CPFXH in PBS for 24 h. The 7d-mineralized CMXG/SXG3-GM12-CPFXH-LAP hydrogel showed dense mineral layers with Ca/P atomic ratio of 1.79, degree of crystalline of 77.3 %, mineral content of 50.8 %, and 2.6 times higher shear modulus than original one. The CMXG/SXG3-GM12-CPFXH-LAP solution was acted as "inks" to "write" word (BONE) and Chinese character ("Gu") manually, and was transferred into moulds to obtain hydrogel constructs with good fidelity of patterns, suggesting injectability and printability. The injectable, mineralizable, biocompatible and drug-loaded CMXG/SXG-GM-CPFXH-LAP hydrogels possess promising applications in bone tissue engineering due to facilitating osteoconductivity, recruiting cells, and reducing inflammation.

The Impact of Implant Surface Modifications on the Osseointegration Process: An Overview

Osseointegration is critical to the long-term success of endosseous dental implants. Surface factors such as roughness, topography, energy, and composition considerably impact this process. Several ways have been used to optimize surface roughness, increase surface area, and improve osseointegration. Subtractive processes such as alumina and titanium dioxide blasting, acid treatment, anodization, and laser peeling are widely utilized. Many additive techniques change implant surfaces, including plasma-sprayed hydroxyapatite, vacuum deposition, sol-gel, dip coating, electrolytic procedures, and nano-hydroxyapatite coating. Recently, biomimetic implant surfaces with calcium phosphate coatings have been created under physiological settings. These coatings can transport osteogenic agents such as bone morphogenetic proteins, growth differentiation factors, and bioactive medications, including bisphosphonates, gentamicin, and tetracycline. Advances in technology have considerably broadened the methods for surface modification of endosseous dental implants. This article provides a comprehensive overview of various surface modification techniques and current trends in oral implantology.

Engineered Living Systems Based on Gelatin: Design, Manufacturing, and Applications

Engineered living systems (ELSs) represent purpose-driven assemblies of living components, encompassing cells, biomaterials, and active agents, intricately designed to fulfill diverse biomedical applications. Gelatin and its derivatives have been used extensively in ELSs owing to their mature translational pathways, favorable biological properties, and adjustable physicochemical characteristics. This review explores the intersection of gelatin and its derivatives with fabrication techniques, offering a comprehensive examination of their synergistic potential in creating ELSs for various applications in biomedicine. It offers a deep dive into gelatin, including its structures and production, sources, processing, and properties. Additionally, the review explores various fabrication techniques employing gelatin and its derivatives, including generic fabrication techniques, microfluidics, and various 3D printing methods. Furthermore, it discusses the applications of ELSs based on gelatin in regenerative engineering as well as in cell therapies, bioadhesives, biorobots, and biosensors. Future directions and challenges in gelatin fabrication are also examined, highlighting emerging trends and potential areas for improvements and innovations. In summary, this comprehensive review underscores the significance of gelatin-based ELSs in advancing biomedical engineering and lays the groundwork for guiding future research and developments within the field.

Polydopamine-based surface coating fabrication on titanium implant by combining a photothermal agent and TiO2 nanosheets for efficient photothermal antibacterial therapy and promoted osteogenic activity

Developing titanium-based dental implants with both excellent antibacterial properties and good osseointegration is crucial for the success of the implant operation and the long-term durability of the implant. In this study, a polydopamine-based coating was created by attaching TiO2 nanosheets-cyanine composites onto the titanium surface, enabling the integration of effective photothermal antibacterial therapy with osseointegration. The exceptional dual-photothermal conversion abilities of polydopamine and cyanine in the coating resulted in outstanding photothermal antibacterial and antibiofilm therapy against four types of bacteria. Furthermore, TiO2 nanosheets promoted the adhesion, proliferation and early osteogenic differentiation of osteoblasts. In an infected dental implant model in rats, the developed coating exhibited potent antibacterial activity and remarkable osteogenic differentiation in the bone, leading to increased bone formation around the implants. This innovative approach, combining photothermal therapy with osteogenic two-dimensional nanomaterials, presents a novel method for surface functionalization of implants to achieve effective antibacterial and osseointegration capabilities.

Application of advanced surface modification techniques in titanium-based implants: latest strategies for enhanced antibacterial properties and osseointegration

Titanium-based implants, renowned for their excellent mechanical properties, corrosion resistance, and biocompatibility, have found widespread application as premier implant materials in the medical field. However, as bioinert materials, they often face challenges such as implant failure caused by bacterial infections and inadequate osseointegration post-implantation. Thus, to address these issues, researchers have developed various surface modification techniques to enhance the surface properties and bioactivity of titanium-based implants. This review aims to outline several key surface modification methods for titanium-based implants, including acid etching, sol-gel method, chemical vapor deposition, electrochemical techniques, layer-by-layer self-assembly, and chemical grafting. It briefly summarizes the advantages, limitations, and potential applications of these technologies, presenting readers with a comprehensive perspective on the latest advances and trends in the surface modification of titanium-based implants.

Biomineral-Based Composite Materials in Regenerative Medicine

Regenerative medicine aims to address substantial defects by amplifying the body's natural regenerative abilities and preserving the health of tissues and organs. To achieve these goals, materials that can provide the spatial and biological support for cell proliferation and differentiation, as well as the micro-environment essential for the intended tissue, are needed. Scaffolds such as polymers and metallic materials provide three-dimensional structures for cells to attach to and grow in defects. These materials have limitations in terms of mechanical properties or biocompatibility. In contrast, biominerals are formed by living organisms through biomineralization, which also includes minerals created by replicating this process. Incorporating biominerals into conventional materials allows for enhanced strength, durability, and biocompatibility. Specifically, biominerals can improve the bond between the implant and tissue by mimicking the micro-environment. This enhances cell differentiation and tissue regeneration. Furthermore, biomineral composites have wound healing and antimicrobial properties, which can aid in wound repair. Additionally, biominerals can be engineered as drug carriers, which can efficiently deliver drugs to their intended targets, minimizing side effects and increasing therapeutic efficacy. This article examines the role of biominerals and their composite materials in regenerative medicine applications and discusses their properties, synthesis methods, and potential uses.

Advances in reparative materials for infectious bone defects and their applications in maxillofacial regions

Infectious bone defects are characterized by the partial loss or destruction of bone tissue resulting from bacterial contaminations subsequent to diseases or external injuries. Traditional bone transplantation and clinical methods are insufficient in meeting the treatment demands for such diseases. As a result, researchers have increasingly focused on the development of more sophisticated biomaterials for improved therapeutic outcomes in recent years. This review endeavors to investigate specific reparative materials utilized for the treatment of infectious bone defects, particularly those present in the maxillofacial region, with a focus on biomaterials capable of releasing therapeutic substances, functional contact biomaterials, and novel physical therapy materials. These biomaterials operate via heightened antibacterial or osteogenic properties in order to eliminate bacteria and/or stimulate bone cells regeneration in the defect, ultimately fostering the reconstitution of maxillofacial bone tissue. Based upon some successful applications of new concept materials in bone repair of other parts, we also explore their future prospects and potential uses in maxillofacial bone repair later in this review. We highlight that the exploration of advanced biomaterials holds promise in establishing a solid foundation for the development of more biocompatible, effective, and personalized treatments for reconstructing infectious maxillofacial defects.

Formation of Amorphous Iron-Calcium Phosphate with High Stability

Amorphous iron-calcium phosphate (Fe-ACP) plays a vital role in the mechanical properties of teeth of some rodents, which are very hard, but its formation process and synthetic route remain unknown. Here, the synthesis and characterization of an iron-bearing amorphous calcium phosphate in the presence of ammonium iron citrate (AIC) are reported. The iron is distributed homogeneously on the nanometer scale in the resulting particles. The prepared Fe-ACP particles can be highly stable in aqueous media, including water, simulated body fluid, and acetate buffer solution (pH 4). In vitro study demonstrates that these particles have good biocompatibility and osteogenic properties. Subsequently, Spark Plasma Sintering (SPS) is utilized to consolidate the initial Fe-ACP powders. The results show that the hardness of the ceramics increases with the increase of iron content, but an excess of iron leads to a rapid decline in hardness. Calcium iron phosphate ceramics with a hardness of 4 GPa can be achieved, which is higher than that of human enamel. Furthermore, the ceramics composed of iron-calcium phosphates show enhanced acid resistance. This study provides a novel route to prepare Fe-ACP, and presents the potential role of Fe-ACP in biomineralization and as starting material to fabricate acid-resistant high-performance bioceramics.