Materials For Bone Tissue Engineering Research Articles

In Vitro Osteogenic Response to Copper-Doped Eggshell-Derived Hyroxyapatite With Macrophage Supplements.

The high bioactivity and biocompatibility of hydroxyapatite (HAP) make it a useful bone graft material for bone tissue engineering. However, the development superior osteoconductive and osteoinductive materials for bone regeneration remains a challenge. To overcome these constraints, Cu-doped hydroxyapatite (HAP(Cu)) from waste eggshells has been produced for bone tissue engineering. The materials produced were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, and photoelectron spectroscopy. The scanning microscopy images revealed that the developed HAP was a rod-like crystalline structure with a typical 80-150 nm diameter. Energy-dispersive x-ray spectroscopy showed that the generated HAP was mostly composed of calcium, oxygen, and phosphorus. The Ca/P molar ratios in eggshell-derived and copper-doped HAP were 1.61 and 1.67, respectively, similar to the commercially available HAP ratio (1.67). The WST-8 assay was used to assess the biocompatibility of HAPs with hBMSCs. HAP(Cu) in the media significantly altered the cytotoxicity of biocompatible HAP(Cu). The osteogenic potential of HAP(Cu) was demonstrated by greater mineralization than that of pure HAP or the control. HAP(Cu) showed higher osteogenic gene expression than pure HAP and the control, indicating its stronger osteogenic potential. Furthermore, we assessed the effects of sample-treated macrophage-derived conditioned medium (CM) on hBMSCs' osteogenesis. CM-treated HAP(Cu) demonstrated a significantly higher osteogenic potential vis-à-vis pure HAP(Cu). These findings revealed that HAP(Cu) with CM significantly improved osteogenesis in hBMSCs and can be explored as a bone graft in bone tissue engineering.

Semiconductor photocatalytic antibacterial materials and their application for bone infection treatment.

Bacterial infection in bone tissue engineering is a severe clinical issue. Traditional antimicrobial methods usually cause problems such as bacterial resistance and biosecurity. Employing semiconductor photocatalytic antibacterial materials is a more controlled and safer strategy, wherein semiconductor photocatalytic materials generate reactive oxygen species under illumination for killing bacteria by destroying their cell membranes, proteins, DNA, etc. In this review, P-type and N-type semiconductor photocatalytic materials and their antibacterial mechanisms are introduced. Type II heterojunctions, P-N heterojunctions, type Z heterojunctions and Schottky junctions have been reported to reduce the recombination of carriers, while element doping, sensitization and up-conversion luminescence expand the photoresponse range. Furthermore, the applications of semiconductor photocatalytic antibacterial materials in bone infection treatment such as osteomyelitis treatment, bone defect repair and dental tissue regeneration are summarized. Finally, the conclusion and future prospects of semiconductor photocatalytic antibacterial materials in bone tissue engineering were analyzed.

Optimizing printability and mechanical properties of poly(3-hydroxybutyrate) (P3HB) biocomposite blends and their biological response to Saos-2 cells

Bone tissue engineering requires scaffolds with three-dimensional structures that facilitate vascularization and new tissue growth. 3D printing, especially through fused deposition modeling (FDM), has emerged as an effective method for creating complex structures with high reproducibility. Early research in this area demonstrated the potential of poly(ε-caprolactone) (PCL) and poly(L-lactide) (PLLA) scaffolds for bone regeneration. Recently, polylactide (PLA) and polyhydroxyalkanoates (PHAs) have garnered attention for their biocompatibility and ability to support cell proliferation. Among PHAs, poly(3-hydroxybutyrate) (P3HB) shows promise due to its intrinsic biocompatibility and resorbability, making it a candidate for FDM-based scaffold fabrication. In the presented study, we aim to develop and optimize a biocompatible P3HB-based composite material for bone tissue engineering, incorporating PLA, hydroxyapatite (HA), and the plasticizer Syncroflex3114 (SN) to enhance mechanical properties and printability. This composite was processed into filaments for 3D printing and characterized through thermal, mechanical, and biological evaluations. Using a design of experiment (DoE) approach, we investigated factors such as temperature performance, warping, degradation, and strength to determine the optimal composition for use in tissue engineering. Four optimal mixture compositions fulfilling the optimization criteria of having the most suitable properties for bone tissue engineering, namely the best printability and maximum mechanical properties,  were obtained. The mixtures were optimized specifically for minimum warping coefficient (0.5); maximum flexural strength (66.9 MPa); maximum compression modulus (2.4 GPa); and maximum compression modulus (2.3 GPa) with a warping coefficient of no more than one at the same time. In conclusion, the study shows a new possible way to effectively develop and test 3D printed P3HB-based scaffolds with specifically optimized material properties.

Chitosan as a Templating Agent of Calcium Phosphate Crystalline Phases in Biomimetic Mineralization: Theoretical and Experimental Studies.

Highlighting the essential role of chitosan (CS), known for its biocompatibility, biodegradability, and ability to promote cell adhesion and proliferation, this study explores its utility in modulating the biomimetic mineralization of calcium phosphate (CaP). This approach holds promise for developing biomaterials suitable for bone regeneration. However, the interactions between the CS surface and in situ precipitated CaP still require further exploration. In the theoretical section, molecular dynamics (MD) simulations demonstrate that, at an appropriate pH level during the prenucleation stage, calcium ions (Ca2+) and hydrogen phosphate ions (HPO42-) form Posner-like clusters. Additionally, the interaction between these clusters and the CS molecule enhances system stability. Together, these phenomena facilitate the transition to subsequent heterogeneous nucleation on the surface of the organic matrix, which is a more controlled process than homogeneous nucleation in solution. Dynamic simulation results suggest that CS acts as a stabilizing matrix at pH 8.0 during biomimetic mineralization. In the experimental section, the effects of pH and the molecular weight of CS were investigated, with a focus on their impact on the crystal structure of the resulting material. X-ray diffraction and scanning electron microscopy analyses reveal that, under conditions of approximately pH 8.0 and a CS molecular weight of 20 000 g/mol, and controlled ion concentration, ultrasound radiation, and temperature, the dominant CaP phases in the material are carbonate-doped hydroxyapatite (CHA) and octacalcium phosphate (OCP). These findings suggest that CS, when adjusted for molecular weight and pH, facilitates the formation of CaP crystal phases that closely resemble the natural inorganic composition of bone, highlighting its protective and regulatory roles in the growth and maturation of crystals during mineralization. The theoretical predictions and experimental outcomes confirm the crucial role of CS as a templating agent, enabling the development of a biomimetic mineralization pathway. CS's ability to guide this process may prove valuable in the design of materials for bone tissue engineering, particularly in developing effective materials for bone tissue healing and regeneration.

Polydopamine-Modified Polycaprolactone Scaffolds Loading Metal Nanoparticles for Bone Tissue Engineering.

Recent advancements in materials synthesis and processing technology, coupled with a deeper understanding of bone nanoscale structure and biology, have provided new avenues for designing bioactive materials in bone tissue regenerative medicine. This Review focuses on the design and application of polydopamine-modified polycaprolactone scaffolds loading metal nanoparticles for bone tissue engineering. We explore their antibacterial properties and their ability to guide cell behavior. Specifically, we discuss the synthesis techniques, protein deposition, morphology variations, and interactions with the extracellular matrix of these scaffolds and biocompatibility and efficacy in promoting bone tissue regeneration in vitro and in vivo. Challenges and unmet needs are reviewed in the development of polymer- and metal-based materials for bone tissue engineering.

A Single-Cell RNA Sequencing Guided Multienzymatic Hydrogel Design for Self-Regenerative Repair in Diabetic Mandibular Defects.

Conventional bone tissue engineering materials struggle to reinstate physiological bone remodeling in a diabetic context, primarily due to the compromised repolarization of proinflammatory macrophages to anti-inflammatory macrophages. Here, leveraging single-cell RNA sequencing (scRNA-seq) technology, the pivotal role of nitric oxide (NO) and reactive oxygen species (ROS) is unveiled in impeding macrophage repolarization during physiological bone remodeling amidst diabetes. Guided by scRNA-seq analysis, we engineer a multienzymatic bone tissue engineering hydrogel scaffold (MEBTHS) composed is engineered of methylpropenylated gelatin hydrogel integrated with ruthenium nanozymes, possessing both Ru0 and Ru4+ components. This design facilitates efficient NO elimination via Ru0 while simultaneously exhibiting ROS scavenging properties through Ru4+. Consequently, MEBTHS orchestrates macrophage reprogramming by neutralizing ROS and reversing NO-mediated mitochondrial metabolism, thereby rejuvenating bone marrow-derived mesenchymal stem cells and endothelial cells within diabetic mandibular defects, producing newly formed bone with quality comparable to that of normal bone. The scRNA-seq guided multienzymatic hydrogel design fosters the restoration of self-regenerative repair, marking a significant advancement in bone tissue engineering.

Piezoelectric Scaffolds as Smart Materials for Bone Tissue Engineering.

Bone repair and regeneration require physiological cues, including mechanical, electrical, and biochemical activity. Many biomaterials have been investigated as bioactive scaffolds with excellent electrical properties. Amongst biomaterials, piezoelectric materials (PMs) are gaining attention in biomedicine, power harvesting, biomedical devices, and structural health monitoring. PMs have unique properties, such as the ability to affect physiological movements and deliver electrical stimuli to damaged bone or cells without an external power source. The crucial bone property is its piezoelectricity. Bones can generate electrical charges and potential in response to mechanical stimuli, as they influence bone growth and regeneration. Piezoelectric materials respond to human microenvironment stimuli and are an important factor in bone regeneration and repair. This manuscript is an overview of the fundamentals of the materials generating the piezoelectric effect and their influence on bone repair and regeneration. This paper focuses on the state of the art of piezoelectric materials, such as polymers, ceramics, and composites, and their application in bone tissue engineering. We present important information from the point of view of bone tissue engineering. We highlight promising upcoming approaches and new generations of piezoelectric materials.

Facile synthesis of in situ bismuth-doped calcium phosphate nanocomposite integrated injectable biopolymer hydrogel slurry for bone regeneration

The bionics of natural bone structures plays an essential role in the selection of materials for bone tissue engineering. Although the content of trace metallic elements in bone is low, they have significant effects on the process of bone growth and metabolism. Up to now, the applications of “green” heavy metals in bone regeneration are limited. Herein, in this study, we present a straightforward one-pot strategy for the synthesis of in situ bismuth-doped amorphous calcium phosphate nanocomposites (RBCP), effectively integrating the beneficial properties of each component. The characterization of these products can be readily optimized by adjusting reaction parameters. Our in vitro studies show that under coordination of each component, the RBCP biomaterial demonstrates distinguished biocompatibility and significantly accelerates vascular pattern formation within just 4 h by stimulating the expression of angiogenesis-related genes in human umbilical vein endothelial cells (HUVECs). In vivo experiments indicate that the incorporation of bismuth effectively enhances bone regeneration and osseointegration in a rat femur defect model. In conclusion, the as-prepared RBCP biomaterials hold promising prospects for treating segmental bone defects, owing to the facile, cost-effective, and eco-friendly preparation process, along with their remarkable capabilities.

Copper ions-photo dual-crosslinked alginate hydrogel for angiogenesis and osteogenesis.

Early healing of bone defects is still a clinical challenge. Many bone-filling materials have been studied, among which photocrosslinked alginate has received significant attention due to its good biocompatibility and morphological plasticity. Although it has been confirmed that photocrosslinked alginate can be used as an extracellular matrix for 3D cell culture, it lacks osteogenesis-related biological functions. This study constructed a copper ions-photo dual-crosslinked alginate hydrogel scaffold by controlling the copper ion concentration. The scaffolds were shaped by photocrosslinking and then endowed with biological functions by copper ions crosslinking. According to in vitro research, the dual-crosslinked hydrogel increased the compressive strength and favored copper dose-dependent osteoblast differentiation and cell surface adherence of rat bone marrow mesenchymal stem cells and the expression of type I collagen (Col1), runt-related transcription factor 2 (Runx2), osteocalcin (OCN), vascular endothelial growth factor (VEGF). In addition, hydrogel scaffolds were implanted into rat skull defects, and more angiogenesis and osteogenesis could be observed in in vivo studies. The above results show that the copper-photo-crosslinked hydrogel scaffold has excellent osseointegration properties and can potentially promote angiogenesis and early healing of bone defects, providing a reference solution for bone tissue engineering materials.

Mg alloy scaffold with spherical/cubic hybrid pores for orthopedic repair

Biodegradable Mg-based scaffolds are regarded as potential bone tissue engineering materials for a promising approach to bone repair. In this work, the spherical/cubic hybrid pore-forming agents were introduced to prepare a porous Mg-based alloy scaffold by the negative salt pattern molding method. The porous Mg-Zn-Ca alloy scaffold containing spherical/cubic hybrid pores exhibited a porosity of about 68.60 % and a surface area ratio of about 7.88 cm2/cm3. The compressive elastic modulus was about 0.32 GPa and the compressive strength was about 4.22 MPa, close to cancellous bone. However, the rapid degradation of Mg alloy scaffold was inadaptive to orthopedic repair. Thus, a calcium phytate coating was prepared on the Mg-based scaffold for surface modification to retard rapid corrosion.

Supramolecular Composite Hydrogel Loaded with CaF2 Nanoparticles Promotes the Recovery of Periodontitis Bone Resorption.

Treatments to reduce periodontal inflammation and rescue periodontitis bone resorption have been of interest to researchers. Bone tissue engineering materials have been gradually used in the treatment of bone defects, but periodontal bone tissue regeneration still faces challenges. Considering the biocompatibility factor, constructing bionic scaffolds with natural extracellular matrix properties is an ideal therapeutic pathway. Based on the pathological mechanism of periodontitis, in this study, short peptide and nanometer inorganic particles were comingled to construct NapKFF-nano CaF2 supramolecular composite hydrogels with different ratios. Material characterization experiments confirmed that the composite hydrogel had suitable mechanical properties and a three-dimensional structure that can function in the resorption region of the alveolar bone and provide spaces for cell proliferation and adhesion. The release of low concentrations of fluoride and calcium ions has been shown to have positive biological effects in both in vivo and in vitro experiments. Vitro experiments confirmed that the composite hydrogel had good biocompatibility and promoted osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Microbiological experiments confirmed that the composite hydrogel inhibited the activity of periodontal pathogenic bacteria. In animal studies, composite hydrogel applied to periodontitis rats in vivo can effectively repair alveolar bone resorption. This composite hydrogel has a simple preparation method and is inexpensive to produce, yet it has antibacterial and osteogenesis-promoting incremental effects, which makes it well suited for the treatment of periodontitis bone resorption, providing a new strategy for periodontal bone tissue engineering.

Bone Regeneration Capabilities of Scaffolds Containing Chitosan and Nanometric Hydroxyapatite-Systematic Review Based on In Vivo Examinations.

In this systematic review, the authors aimed to investigate the state of knowledge on in vivo evaluations of chitosan and nanometric hydroxyapatite (nanohydroxyapatite, nHAp) scaffolds for bone-tissue regeneration. In March 2024, an electronic search was systematically conducted across the PubMed, Cochrane, and Web of Science databases using the keywords (hydroxyapatite) AND (chitosan) AND (scaffold) AND (biomimetic). Methodologically, the systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) protocol to the letter. Initially, a total of 375 studies were screened, and 164 duplicates were removed. A further 188 articles were excluded because they did not correspond to the predefined topics, and an additional 3 articles were eliminated due to the inability to obtain the full text. The final compilation included 20 studies. All publications indicated a potential beneficial effect of the scaffolds in in vivo bone defect repair. A beneficial effect of hydroxyapatite as a scaffold component was observed in 16 studies, including greater mechanical resistance, cellular differentiation, and enhanced bone damage regeneration. The addition of chitosan and apatite ceramics, which combined the strengths of both materials, had the potential to become a useful bone-tissue engineering material.

Surface Functionalization of 3D-Printed Scaffolds with Seed-Assisted Hydrothermally Grown ZnO Nanoarrays for Bone Tissue Engineering.

Bioactive metal-based nanostructures, particularly zinc oxide (ZnO), are promising materials for bone tissue engineering. However, integrating them into 3D-printed polymers using traditional blending methods reduces the cell performance. Alternative surface deposition techniques often require extreme conditions that are unsuitable for polymers. To address these issues, we propose a metal-assisted hydrothermal synthesis method to modify 3D printed polycaprolactone (PCL) scaffolds with ZnO nanoparticles (NPs), facilitating the growth of ZnO nanoarrays (NAs) at a low-temperature (55 °C). Physicochemical characterizations revealed that the ZnO NPs form both physical and chemical bonds with the PCL surface; chemical bonding occurs between the carboxylate groups of PCL and Zn(OH)2 during seed deposition and hydrothermal synthesis. The ZnO NPs and NAs grown for a longer time (18 h) on the surface of PCL scaffolds exhibit significant proliferation and early differentiation of osteoblast-like cells. The proposed method is suitable for the surface modification of thermally degradable polymers, opening up new possibilities for the deposition of diverse metals.

A Review on Silver Nanoparticles Based Biomaterials for Bone Tissue Engineering and Medical Applications

Silver nanoparticles (AgNPs) are being studied extensively as nanostructures for novel and enhanced biomedical applications. Nanoparticles in bone grafts have been shown to speed up fracture healing by providing a finer structure for bone tissue engineering. They are known to have excellent antimicrobial properties due to their high surface-to-volume ratio and small particle size, without affecting the material's mechanical properties. AgNPs' distinct property makes them the preferred filler in a wide range of biomaterials, where they play an important role in enhancing properties. AgNP-containing biomaterials can be easily tailored to meet specific requirements in the development of bone tissue. Adjusting size, shape, composition, and surface charge can enhance their effectiveness in interacting with bone cells, promoting cell attachment, and delivering growth factors. Using AgNP-based biomaterials can help prevent or reduce the formation of biofilms. The utilization of these materials in bone tissue engineering has demonstrated potential in treating musculoskeletal conditions and bone traumas. They are versatile for various applications such as bone implants, scaffolds, wound dressings, and antibiotic delivery systems. This review will cover several special topics, including silver-based biomaterials, toxic properties, morphology and mechanical properties of silver-based biomaterials, and applications of silver-based biomaterials in medical applications.

The effect of surface roughness and wettability on the adhesion and proliferation of Saos-2 cells seeded on 3D printed poly(3-hydroxybutyrate)/polylactide (PHB/PLA) surfaces

The aim of this work is to explore the effect of surface characteristics of the 3D printed scaffolds on their suitability for Saos-2 cells growth. Two promising materials for bone tissue engineering were examined, both containing poly(3-hydroxybutyrate)/poly(d,l-lactide) plasticized blend and one of them filled with bioactive tricalcium phosphate. The surface free energy (SFE) of samples was determined by contact angle measurement with four liquids. For non-filled sample the water contact angle (WCA) was 74° and its SFE was 40 mN m−1. The composite sample exhibited substantially decreased WCA, 61°. Moreover, the addition of the tricalcium phosphate caused doubling of the polar component of the SFE which increased by a total of 13%. 3D printed surfaces prepared by fused deposition modeling method showed a profound increase of WCA due to the increase in their surface roughness which was analyzed by confocal microscopy. The change in wetting properties strongly affected the behavior of Saos-2 cells on printed surfaces. The number of cells as measured by DNA quantification linearly decreased with increasing surface WCA. The highest number of cells was observed on the pressed samples and 3D printed surfaces made of simple lines and a grid with 50 μm gap between lines. The favored surfaces exhibit WCA under 80° which is important information for the future design of the scaffolds.

Electrochemical Mineralization Regulates Hydroxyapatite Deposition of Silk Fibroin Nanofibers for Promoting Osteogenic Differentiation of Human Mesenchymal Stem Cells

ABSTRACTScaffold and stem cells are the key elements in the procedure of bone repair. Bombyx mori silk fibroin (SF) is the proper material for bone tissue engineering due to its biocompatibility and its easy to obtain nanofiber structure. The suitable cell substrate is also an important factor because different cells have different adaptations to composite. For this case, selecting a scaffold that can promote osteogenic differentiation of various cells is crucial and meaningful. In this work, hydroxyapatite (HA) was deposited precisely onto each silk nanofiber by electrochemical mineralization (EC) to form SF/HA. SF/HA can promote the proliferation and osteogenic differentiation of both human bone marrow mesenchymal‐derived stem cells (hMSCs) and human adipose‐derived mesenchymal stem cells (hAMSCs). It also promot the expression of alkaline phosphatase (ALP) and osteogenic differentiation related genes. Western blot analyses show mitogen‐activated protein kinase (MAPK) signal pathway is regulated by SF/HA. Therefore, the study provides a proper method to obtain a good composite SF/HA and it promotes the osteogenic differentiation of both hMSCs and hAMSCs.

Fabrication and Biomedical Application of Alginate Composite Hydrogels in Bone Tissue Engineering: A Review.

Nowadays, as a result of the frequent occurrence of accidental injuries and traumas such as bone damage, the number of people causing bone injuries or fractures is increasing around the world. The design and fabrication of ideal bone tissue engineering (BTE) materials have become a research hotspot in the scientific community, and thus provide a novel path for the treatment of bone diseases. Among the materials used to construct scaffolds in BTE, including metals, bioceramics, bioglasses, biomacromolecules, synthetic organic polymers, etc., natural biopolymers have more advantages against them because they can interact with cells well, causing natural polymers to be widely studied and applied in the field of BTE. In particular, alginate has the advantages of excellent biocompatibility, good biodegradability, non-immunogenicity, non-toxicity, wide sources, low price, and easy gelation, enabling itself to be widely used as a biomaterial. However, pure alginate hydrogel as a BTE scaffold material still has many shortcomings, such as insufficient mechanical properties, easy disintegration of materials in physiological environments, and lack of cell-specific recognition sites, which severely limits its clinical application in BTE. In order to overcome the defects of single alginate hydrogels, researchers prepared alginate composite hydrogels by adding one or more materials to the alginate matrix in a certain proportion to improve their bioapplicability. For this reason, this review will introduce in detail the methods for constructing alginate composite hydrogels, including alginate/polymer composite hydrogels, alginate/bioprotein or polypeptide composite hydrogels, alginate/bioceramic composite hydrogels, alginate/bioceramic composite hydrogels, and alginate/nanoclay composite hydrogels, as well as their biological application trends in BTE scaffold materials, and look forward to their future research direction. These alginate composite hydrogel scaffolds exhibit both unexceptionable mechanical and biochemical properties, which exhibit their high application value in bone tissue repair and regeneration, thus providing a theoretical basis for the development and sustainable application of alginate-based functional biomedical materials.

Preparation and Structure-Property Relationship Study of Piezoelectric-Conductive Composite Polymer Nanofiber Materials for Bone Tissue Engineering.

This study aimed to develop Janus-, cross-network-, and coaxial-structured piezoelectric-conductive polymer nanofibers through electrospinning to mimic the piezoelectricity of bone and facilitate the conduction of electrical signals in bone tissue repair. These nanofibers were constructed using the piezoelectric polymer polyvinylidene fluoride, and the conductive fillers reduced graphene oxide and polypyrrole. The influence of structural features on the electroactivity of the fibers was also explored. The morphology and components of the various structural samples were characterized using SEM, TEM, and FTIR. The electroactivity of the materials was assessed with a quasi-static d33 meter and the four-probe method. The results revealed that the piezoelectric-conductive phases were successfully integrated. The Janus-structured nanofibers demonstrated the best electroactivity, with a piezoelectric constant d33 of 24.5 pC/N and conductivity of 6.78 × 10-2 S/m. The tensile tests and MIP measurements showed that all samples had porosity levels exceeding 70%. The tensile strength of the Janus and cross-network structures exceeded that of the periosteum (3-4 MPa), with average pore sizes of 1194.36 and 2264.46 nm, respectively. These properties indicated good mechanical performance, allowing material support while preventing fibroblast invasion. The CCK-8 and ALP tests indicated that the Janus-structured samples were biocompatible and significantly promoted the proliferation of MC3T3-E1 cells.

In vitro biocompatibility and stem cell regenerative assessment of hollow hydroxyapatite spheres deposited wollastonite/Ca2P6O17/TCP/doped-wollastonite scaffolds

This research examines the biological behavior of multilayer ceramic-glass scaffolds for bone tissue engineering. The scaffolds consist of a high-strength core of wollastonite and P6 (Ca2P6O17), with a sequential coating of TCP and wollastonite doped with Na+, K+ and Mg2+ ions to confer bioactivity to the system. Two formulations were investigated: a magnesium-deficient one, which served as a microstructure control, and a magnesium-rich one in which hollow hydroxyapatite (HA) spheres precipitated after one week of immersion in simulated body fluid (SBF). These formulations are denoted as C-Scaffold and HA-Scaffold, respectively. Further exploration and comparison of the physiological effects of both scaffolds is necessary to fully understand their potential as drug release agents and associated therapeutic advantages. The study considered aspects such as protein adhesion, cell morphology, and the inflammatory response. The results showed that the HA-Scaffold had over 34 % more plasma protein adhesion compared to the C-Scaffold. Similarly, cell proliferation assays showed increased cell growth in both HFF-1 fibroblasts and mesenchymal stem cells (MSCs) treated with HA-Scaffold compared to C-Scaffold. This may be attributed to the higher protein adsorption, which acts as a facilitator for cell adhesion. Three-dimensional photography from computerized microtomography confirmed that the scaffolds have a similar morphology and porosity to the intricate structure of trabecular bone in the humeral head. The study shows that the scaffolds made of Wollastonite/Ca2P6O17/TCP/Doped-Wollastonite with HA hollow spheres are highly suitable for use in this bone segment due to their overall porosity of over 86 % and approximate mechanical strength of 1.6 MPa. These findings demonstrate the biocompatibility and enhanced biological properties of the scaffolds, making them an excellent material for bone tissue engineering.

An intelligent controlled release hydrogel with photothermal effect for the treatment of bone defects

To solve the difficulty of natural healing in patients with severe bone defects, and the challenges of insufficient autologous bone graft material and large incisions in conventional surgery, we were designed an intelligent co-regulated hydrogel system with NIR response. The goal is to be able to prevent inflammation and bacterial adhesion, thereby promoting repair and development of the bone defect area. The hydrogel system consisted of hyaluronic acid, carboxymethyl chitosan and Pht-loaded PDA-encapsulated ZIF-8 NPs (Pht@ZIF-8@PDA) by Schiff base reaction. Compared to high-temperature photothermal therapy (PTT), which destroyed surrounding healthy cells, the present study was based on a new strategy of mild photothermal therapy (42.5 ± 1.2 °C) and leaded to a better promotion of osteogenesis. NIR activated the photothermal properties of PDA in scaffolds, intelligently released Pht and Zn2+, inhibited Escherichia coli and Staphylococcus aureus (inhibition rate ≥ 96 %), and promoted bone regeneration in the rat model. Meanwhile, it could promote bone regeneration by upregulating osteogenic factors and stimulating the expression of proteins related to BMP/SMAD signaling pathway. The research highlights the potential applications of synergistically modulated hydrogels, which opens up a new application path for this material in bone tissue engineering, regenerative medicine, and other related fields.