Osteoblast response to Vitamin D3 loaded cellulose enriched hydroxyapatite Mesoporous silica nanoparticles composite

A facile and smart strategy to enhance bone regeneration with efficient vitamin D3 delivery through sterosome technology

The spontaneous healing of critical-sized bone defects is often limited, posing an increased risk of complications and suboptimal outcomes. Osteogenesis, a complex process central to bone formation, relies significantly on the pivotal role of osteoblasts. Despite the well-established osteogenic properties of vitamin D3 (VD3), its lipophilic nature confines administration to oral or muscle injection routes. Therefore, a strategic therapeutic approach involves designing a multifunctional carrier to enhance efficacy, potentially incorporating it into the delivery system. Here, we introduce an innovative sterosome-based delivery system, utilizing palmitic acid (PA) and VD3, aimed at promoting osteogenic differentiation and facilitating post-defect bone regeneration. The delivery system exhibited robust physical characteristics, including excellent stability, loading efficiency, sustained drug release and high cellular uptake efficiency. Furthermore, comprehensive investigations demonstrated outstanding biocompatibility and osteogenic potential in both 2D and 3D in vitro settings. A critical-sized calvarial defect model in mice recapitulated the notable osteogenic effects of the sterosomes in vivo. Collectively, our research proposes a clinically applicable strategy for bone healing, leveraging PA/VD3 sterosomes as an efficient carrier to deliver VD3 and enhance bone regenerative effects.

Research Progress of Design Drugs and Composite Biomaterials in Bone Tissue Engineering

Bone, like most organs, has the ability to heal naturally and can be repaired slowly when it is slightly injured. However, in the case of bone defects caused by diseases or large shocks, surgical intervention and treatment of bone substitutes are needed, and drugs are actively matched to promote osteogenesis or prevent infection. Oral administration or injection for systemic therapy is a common way of administration in clinic, although it is not suitable for the long treatment cycle of bone tissue, and the drugs cannot exert the greatest effect or even produce toxic and side effects. In order to solve this problem, the structure or carrier simulating natural bone tissue is constructed to control the loading or release of the preparation with osteogenic potential, thus accelerating the repair of bone defect. Bioactive materials provide potential advantages for bone tissue regeneration, such as physical support, cell coverage and growth factors. In this review, we discuss the application of bone scaffolds with different structural characteristics made of polymers, ceramics and other composite materials in bone regeneration engineering and drug release, and look forward to its prospect.

A novel peptide isolated from Catla skin collagen acts as a self-assembling scaffold promoting nucleation of calcium-deficient hydroxyapatite nanocrystals

Catla collagen hydrolysate (CH) was fractionated by chromatography and each fraction was subjected to HA nucleation, with the resultant HA-fraction composites being scored based on the structural and functional group of the HA formed. The process was repeated till a single peptide with augmented HA nucleation capacity was obtained. The peptide (4.6 kDa), exhibited high solubility, existed in polyproline-II conformation and displayed a dynamic yet stable hierarchical self-assembling property. The 3D modelling of the peptide revealed multiple calcium and phosphate binding sites and a high propensity to self-assemble. Structural analysis of the peptide-HA crystals revealed characteristic diffraction planes of HA with mineralization following the (002) plane, retention of the self-assembled hierarchy of the peptide and intense ionic interactions between carboxyl groups and calcium. The peptide-HA composite crystals were mostly of 25-40 nm dimensions and displayed 79% mineralization, 92% crystallinity, 39.25% porosity, 12GPa Young's modulus and enhanced stability in physiological pH. Cells grown on peptide-HA depicted faster proliferation rates and higher levels of osteogenic markers. It was concluded that the prerequisite for HA nucleation by a peptide included: a conserved sequence with a unique charge topology allowing calcium chelation and its ability to form a dynamic self-assembled hierarchy for crystal propagation.

Cellulose-based composite scaffolds for bone tissue engineering and localized drug delivery

Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues, especially in large bone defects. To improve the reconstruction of the damaged bones, tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants. Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration. Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications. Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity, biocompatibility, biodegradability, availability through renewable resources, and the low cost of preparation and processing. Furthermore, cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair. This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration, including cellulose-organic composites, cellulose-inorganic composites, cellulose-organic/inorganic composites. We will also highlight the physicochemical, mechanical, and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.

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Cellulose and its derivatives are renewable and biodegradable natural polymers that with great potential for bone tissue engineering.

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Cellulose-based materials can be used various therapeutics directly to the bone to achieve bone regeneration.

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Bioinks made of cellulose-based materials hold great promise to develop patient specific solutions for bone repair using 3D printing.

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Challenges associated with inaccuracies in existing preclinical models, sterilization regulatory barriers still need to be addressed before clinical translation.

Nano-Hydroxyapatite Composite Scaffolds Loaded with Bioactive Factors and Drugs for Bone Tissue Engineering

Nano-hydroxyapatite (n-HAp) is similar to human bone mineral in structure and biochemistry and is, therefore, widely used as bone biomaterial and a drug carrier. Further, n-HAp composite scaffolds have a great potential role in bone regeneration. Loading bioactive factors and drugs onto n-HAp composites has emerged as a promising strategy for bone defect repair in bone tissue engineering. With local delivery of bioactive agents and drugs, biological materials may be provided with the biological activity they lack to improve bone regeneration. This review summarizes classification of n-HAp composites, application of n-HAp composite scaffolds loaded with bioactive factors and drugs in bone tissue engineering and the drug loading methods of n-HAp composite scaffolds, and the research direction of n-HAp composite scaffolds in the future is prospected.

Locally Applied Repositioned Hormones for Oral Bone and Periodontal Tissue Engineering: A Narrative Review

Bone and periodontium are tissues that have a unique capacity to repair from harm. However, replacing or regrowing missing tissues is not always effective, and it becomes more difficult as the defect grows larger. Because of aging and the increased prevalence of debilitating disorders such as diabetes, there is a considerable increase in demand for orthopedic and periodontal surgical operations, and successful techniques for tissue regeneration are still required. Even with significant limitations, such as quantity and the need for a donor area, autogenous bone grafts remain the best solution. Topical administration methods integrate osteoconductive biomaterial and osteoinductive chemicals as hormones as alternative options. This is a promising method for removing the need for autogenous bone transplantation. Furthermore, despite enormous investigation, there is currently no single approach that can reproduce all the physiologic activities of autogenous bone transplants. The localized bioengineering technique uses biomaterials to administer different hormones to capitalize on the host’s regeneration capacity and capability, as well as resemble intrinsic therapy. The current study adds to the comprehension of the principle of hormone redirection and its local administration in both bone and periodontal tissue engineering.

Vitamin D3 Stimulates Proliferation Capacity, Expression of Pluripotency Markers, and Osteogenesis of Human Bone Marrow Mesenchymal Stromal/Stem Cells, Partly through SIRT1 Signaling

The biology of vitamin D3 is well defined, as are the effects of its active metabolites on various cells, including mesenchymal stromal/stem cells (MSCs). However, the biological potential of its precursor, cholecalciferol (VD3), has not been sufficiently investigated, although its significance in regenerative medicine—mainly in combination with various biomaterial matrices—has been recognized. Given that VD3 preconditioning might also contribute to the improvement of cellular regenerative potential, the aim of this study was to investigate its effects on bone marrow (BM) MSC functions and the signaling pathways involved. For that purpose, the influence of VD3 on BM-MSCs obtained from young human donors was determined via MTT test, flow cytometric analysis, immunocytochemistry, and qRT-PCR. Our results revealed that VD3, following a 5-day treatment, stimulated proliferation, expression of pluripotency markers (NANOG, SOX2, and Oct4), and osteogenic differentiation potential in BM-MSCs, while it reduced their senescence. Moreover, increased sirtuin 1 (SIRT1) expression was detected upon treatment with VD3, which mediated VD3-promoted osteogenesis and, partially, the stemness features through NANOG and SOX2 upregulation. In contrast, the effects of VD3 on proliferation, Oct4 expression, and senescence were SIRT1-independent. Altogether, these data indicate that VD3 has strong potential to modulate BM-MSCs’ features, partially through SIRT1 signaling, although the precise mechanisms merit further investigation.

Nano-hydroxyapatite as a delivery system: overview and advancements

Nano-hydroxyapatite is being investigated as vital components of implants and dental and tissue engineering devices. It is found as a bone replacement due to its non-toxicity and cytocompatibility with dental tissues and bone. The reality that nanocrystalline hydroxyapatite can be made of porous granules and scaffolds. Additionally, it has a massive loading potential indicating its use as a transporter for drugs or a regulated drug release mechanism in pharmaceutical research. This review aims to present existing nano-hydroxyapatite research developments as a drug carrier employed in bone tissue disorders locally and deliver poorly soluble drugs with reduced bioavailability. We have discussed the nano-hydroxyapatite role in the delivery of drugs (i.e. anti-resorptive, anti-cancer, and antibiotics), proteins, genetic material, and radionuclides.

Effect of mesoporous silica and its combination with hydroxyapatite on the regeneration of rabbit's bone defects: A pilot study

BACKGROUND

Bone volume augmentation is a routine technique used in oral implantology and periodontology. Advances in the surgical techniques and the biomaterials field have allowed a greater accessibility to these treatments. Nevertheless, dehiscence and fenestrations incidence during dental implant procedures are still common in patients with bone loss.

OBJECTIVE

The main objective is to evaluate in a pilot experimental study the biological response to mesoporous silica (MS) hybrid scaffolds and its regenerative capacity in different formulations.

METHODS

Two defects per rabbit tibia were performed (one for control and other for test) and the biomaterials tested in this study have been used to fill the bone defects, prepared in two different formulations (3D hybrid scaffolds or powdered material, in 100% pure MS form, or 50% MS with 50% hydroxyapatite (HA). Euthanasia was performed 4 months after surgery for bone histopathological study and radiographic images were acquired by computerized microtomography.

RESULTS

Results showed that radiographically and histopathologically pure MS formulations lead to a lower biological response, e.g when formulated with HA, the osteogenic response in terms of osteoconduction was greater.

CONCLUSIONS

We observed tolerance and lack of toxicity of the MS and HA, without registering any type of local or systemic allergic reaction.

Osteoblast cell viability over ultra-long tricalcium phosphate nanocrystal-based methacrylate chitosan composite for bone regeneration

Bio-ceramic morphology plays a crucial role in bone repair and regeneration. It is extensively utilized in bone scaffold synthesis due to its better biological system activity and biocompatibility. Here, the ultra-long tricalcium phosphate (UTCP) was synthesized with the assistance of the ultrasonication method. The UTCP is modified as a scaffold by the reinforcement of methacrylate chitosan (MAC) polymer. The functionality of UTCP, UTCP combined MAC, methotrexate (MTX) loaded composites was characterized through FTIR (Fourier transform infrared spectroscopy). The crystalline natures are investigated by the XRD (X-ray diffraction), and results shows the ultra-long tricalcium phosphate crystalline phase is not altered after the reinforcement of MAC polymer and loading of MTX drugs. The morphological analyses were observed through electron microscopic analysis, and rod, polymer-coated rod structures were observed. The UTCP/MAC composite mechanical stress was increased from 1813 Pa of UTCP to 4272 Pa. The MTX loading and release was achieved 79.0 % within 3 h and 76.15 % at 20 h respectively. The UTCP/MAC and UTCP/MAC/MTX's viability investigated osteoblast like the cells (MG-63), and the MTX loaded UTCP/MAC composite exhibits good viability behaviors up to 96.0 % in 14 days. The results confirm the higher compatibility of the composite and profitable cell growth. It may be suitable for bone implantation preparation and it helps in faster regeneration of bone tissue after the in-vivo and clinical evaluation.

In-vivo Investigations of Hydroxyapatite/Co-polymeric Composites Coated Titanium Plate for Bone Regeneration

A perfect mimic of human bone is very difficult. Still, the latest advancement in biomaterials makes it possible to design composite materials with morphologies merely the same as that of bone tissues. In the present work is the fabrication of selenium substituted Hydroxyapatite (HAP-Se) covered by lactic acid (LA)-Polyethylene glycol (PEG)-Aspartic acid (AS) composite with the loading of vincristine sulfate (VCR) drug (HAP-Se/LA-PEG-AS/VCR) for twin purposes of bone regenerations. The HAP-Se/LA-PEG-AS/VCR composite coated on titanium implant through electrophoretic deposition (EPD). The prepared composite characterized using FTIR, XRD techniques to rely on the composites' chemical nature and crystalline status. The morphology of the composite and the titanium plate with the composite coating was investigated by utilizing SEM, TEM instrument techniques, and it reveals the composite has porous morphology. The drug (VCR) load in HAP-Se/LA-PEG-AS and releasing nature were investigated through UV-Visible spectroscopy at the wavelength of 295 nm. In vitro study of SBF treatment shows excellent biocompatibility to form the HAP crystals. The viability against MG63 and toxicity against Saos- 2 cells have expressed the more exceptional biocompatibility in bone cells and toxicity with the cancer cells of prepared composites. The in-vivo study emphasizes prepared biomaterial suitable for implantation and helps accelerate bone regeneration on osteoporosis and osteosarcoma affected hard tissue.

Osteogenic potential of the growth factors and bioactive molecules in bone regeneration

The growing need for treatment of the impaired bone tissue has resulted in the quest for the improvement of bone tissue regeneration strategies. Bone tissue engineering is trying to create bio-inspired systems with a coordinated combination of the cells, scaffolds, and bioactive factors to repair the damaged bone tissue. The scaffold provides a supportive matrix for cell growth, migration, and differentiation and also, acts as a delivery system for bioactive factors. Bioactive factors including a large group of cytokines, growth factors (GFs), peptides, and hormonal signals that regulate cellular behaviors. These factors stimulate osteogenic differentiation and proliferation of cells by activating the signaling cascades related to ossification and angiogenesis. GFs and bioactive peptides are significant parts of the bone tissue engineering systems. Besides, the use of the osteogenic potential of hormonal signals has been an attractive topic, particularly in osteoporosis-related bone defects. Due to the unstable nature of protein factors and non-specific effects of hormones, the engineering of scaffolds to the controlled delivery of these bioactive molecules has paramount importance. This review updates the growth factors, engineered peptides, and hormones that are used in bone tissue engineering systems. Also, discusses how these bioactive molecules may be linked to accelerating bone regeneration.

In Vivo Assessment of a Hydroxyapatite/κ-Carrageenan-Maleic Anhydride-Casein/Doxorubicin Composite-Coated Titanium Bone Implant

Here, we focus on the fabrications of an osteosarcoma implant for bone repair via the development of a hydroxyapatite/κ-carrageenan-maleic anhydride/casein with doxorubicin (HAP/κ-CA-MA-CAS/DOX) composite-deposited titanium (Ti) plate. The HAP/κ-CA-MA-CAS/DOX material was coated on the Ti plate through the EPD method (electrophoretic deposition), applying direct current (DC) signals to deposit the composite on the surface of the Ti plate. The physicochemical and morphological possessions and biocompatibility in vitro of the prepared nanocomposite were examined to assess its prospective effectiveness for purposes of bone regeneration. Excellent biocompatibility and elevated osteoconductivity were confirmed using MG63 osteoblast-like cells. In vivo studies were performed at tibia sites in Wistar rats, and rapid bone regeneration was detected at four weeks in defective bone. Overall, the studies demonstrate that the HAP/κ-CA-MA-CAS/DOX composite enhances the biocompatible and cell-stimulating biointerface of Ti metallic implants. As such, HAP/κ-CA-MA-CAS/DOX implants are viable prospects for osteosarcoma-affected bone regeneration.

Recent advances in the application of mesoporous silica-based nanomaterials for bone tissue engineering

Silica nanomaterials (SNMs) and their composites have recently been investigated as scaffolds for bone tissue engineering. SNM scaffolds possess the ability to encourage bone cell growth and also allow the simultaneous delivery of biologically active biomolecules that are encapsulated in the mesopores. Their high mechanical strength, low cytotoxicity, ability to stimulate both the proliferation and osteogenic differentiation of progenitor cells make the SNMs appropriate scaffolds. Their physiochemical properties facilitate the cell spreading process, allow easy access to nutrients and help the cell-cell communication process during bone tissue engineering. The ability to deliver small biomolecules, such as dexamethasone, different growth factors, vitamins and mineral ions depends on the morphology, porosity, and crystallinity of SNMs and their composites with other polymeric materials. In this review, the abilities of SNMs to perform as suitable scaffolds for bone tissue engineering are comprehensively discussed.

Zirconia toughened hydroxyapatite biocomposite formed by a DLP 3D printing process for potential bone tissue engineering

The construction of ceramic components with UV curing is a developing trend by an additive manufacturing (AM) technology, due to the excellent advantages of high precision selective fixation and rapid prototyping, the application of this technology to bone defect repair had become one of the hotspots of research. Hydroxyapatite (HAP) is one of the most popular calcium phosphate biomaterials, which is very close to the main ingredient of human bones. Thus, hydroxyapatite biomaterials are popular as bone graft materials. In summary, the preparation of HAP bioceramics by a 3D printing of digital light processing (DLP) is a promising work. However, the preparation of HAP hybrid suspensions with high solid loading and good fluidity that can be printed by DLP encountered some challenges. Therefore, the purpose of this work is to improve and develop a novel UV-curing suspension with a high solids loading, which the suspension with the hydrodynamic properties and stability are suitable for DLP printer, in order to compensate for the brittleness of HAP ceramics itself to a certain extent, a low amount of zirconia was added in the suspension as an additive to fabricate a zirconia toughened HAP bioceramic composite by a DLP of 3D printing. In this work, the HAP powder was pre-modified by two organic modifiers to improve the compatibility in the acrylic resin system, and the addition of the castor oil phosphate further reduced the shear stress of the suspension to ensure strong liquidity. The UV suspension with 60 wt% powder particle loading had a minimum viscosity of 7495 mPa·s at 30 rpm, which was vacuum sintered at 1100 °C, 1200 °C, and 1250 °C, respectively. The composite ceramics (with 6 wt% ZrO₂) at 1200 °C had a relative density of 90.7%, while the sintered samples at 1250 °C had stronger tensile strength and bending strength. The toughening effect of zirconia incorporation on HAP ceramics was also confirmed by the change of tensile modulus and bending modulus, whereas the corresponding mechanical properties were also significantly enhanced.

Fabrication of bioactive rifampicin loaded κ-Car-MA-INH/Nano hydroxyapatite composite for tuberculosis osteomyelitis infected tissue regeneration

Biocompatible polymers and ceramic materials have been identified as vital components to fabricate drug delivery and tissue engineering applications because of their high drug loading capability, sustained release and higher mechanical strength with remarkable in-vivo bioavailability. In the present work, initially we designed κ-carrageenan grafted with maleic anhydride and then reacted it with isoniazid drug (κ-Car-MA-INH). The polymeric system was cross linked with nanohydroxyapatite (NHAP) via electrostatic interaction followed by the addition of rifampicin (RF) and loaded to fabricate κ -Car-MA-INH/NHAP/RF nanocomposites. The chemical modification and interaction of drug with the polymeric-ceramic system were characterised by Fourier Transform Infrared spectroscopy (FT-IR). The zeta potential of the κ -Car-MA-INH/NHAP/RF nanocomposite was observed to be -20.04 mV using Zetasizer. The in vitro drug release studies demonstrated that the nanocomposite releases 76% of RF and 82% of INH in 12 days at pH 5.5. Scanning Electron Microscope analysis revealed the structural deformation of Staphylococcus aureus and Klebsiella pneumoniae upon treatment with this nanocomposite. By using ex-vivo studies combined with physio-chemical characterization methods on the erythrocytes, L929 and MG-63 cell lines, this composite was found to be biocompatible, non-cytotoxic and inducing cell proliferation with less significant hemolysis. Thus, our modified drug delivery nanocomposites afforded higher drug bioavailability with large potential for fabrication as long-acting drug delivery nanocomposites, especially with hydrophobic drugs inducing the growth of osteoblastic bone cells.

Cisplatin-Loaded Graphene Oxide/Chitosan/Hydroxyapatite Composite as a Promising Tool for Osteosarcoma-Affected Bone Regeneration

Presently, tissue engineering approaches have been focused toward finding new potential scaffolds with osteoconductivity on bone-disease-affected cells. This work focused on the cisplatin (CDDP)-loaded graphene oxide (GO)/hydroxyapatite (HAP)/chitosan (CS) composite for enhancing the growth of osteoblast cells and prevent the development of osteosarcoma cells. The prepared composites were characterized for the confirmation of composite formation using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction techniques. A flowerlike morphology was observed for the GO/HAP/CS-3/CDDP composite. UV-vis spectroscopy was used to observe the controlled release of CDDP from the GO/HAP/CS-3/CDDP composite, and 67.34% of CDDP was released from the composite over a time period of 10 days. The GO/HAP/CS-3/CDDP nanocomposites showed higher viability in comparison with GO/HAP/CS-3 on MG63 osteoblast-like cells and higher cytotoxicity against cancer cells (A549). The synthesized composite was found to show enhanced proliferative, adhesive, and osteoinductive effects on the alkaline phosphatase activity of osteoblast-like cells. Our results suggested that the CDDP-loaded GO/HAP/CS-3 nanocomposite has an immense prospective as a bone tissue replacement in the bone-cancer-affected tissues.