Chitosan–amylopectin/hydroxyapatite and chitosan–chondroitin sulphate/hydroxyapatite composite scaffolds for bone tissue engineering

Antibacterial and anticancerous drug loading kinetics for (10-x)CuO-xZnO-20CaO-60SiO2-10P2O5 (2 ≤ x ≤ 8) mesoporous bioactive glasses

In the present study, antibacterial and anticancerous drug loading kinetics for the (10-x)CuO-xZnO-20CaO-60SiO₂-10P₂O₅ (2≤x≤8, varying in steps of 2) mesoporous bioactive glasses (MBGs) have been studied. XRD analysis of the as prepared glass samples proved its amorphous nature. Scanning electron microscopy (SEM) revealed the apatite layer formation on the surface of the MBGs after soaking for 15 days in SBF. Ion dissolution studies of calcium, phosphorous and silicon have been performed using inductively coupled plasma (ICP). FTIR and Raman analysis depicted about the presence of various bonds and groups present in the glasses. The pore size of MBGs lies in the range of 4.2-9.7 nm. Apart from this, specific surface area of the MBGs varied from 263 to 402 cm²/g. The MBGs were loaded with Doxorubicin (DOX), Vancomycin (VANCO) and Tetracycline (TETRA) drugs among which, the decreasing copper content influenced the loading properties of doxorubicin and tetracycline drugs. Vancomycin was fully loaded almost in all the MBGs, whereas other drugs depicted varying loading with respect to the copper content.

Thermosensitive chitosan gels containing calcium glycerophosphate for bone cell culture

In this article, properties of thermosensitive chitosan hydrogels prepared with the use of chitosan chloride with β-glycerophosphate disodium salt pentahydrate enriched with calcium glycerophosphate are presented and compared with chitosan hydrogels with β-glycerophosphate disodium salt pentahydrate. The study is focused on the determination of hydrogel structure and biological testing of hydrogels with human osteoblasts line Saos-2. The structure of gels was visualized by scanning electron microscopy and was investigated by infrared spectroscopy. The crystallinity of gel structure was determined by X-ray diffraction analysis and thermal effects were determined using differential scanning calorimetry thermograms.

Magnesium incorporated chitosan based scaffolds for tissue engineering applications

Chitosan based porous scaffolds are of great interest in biomedical applications especially in tissue engineering because of their excellent biocompatibility in vivo, controllable degradation rate and tailorable mechanical properties. This paper presents a study of the fabrication and characterization of bioactive scaffolds made of chitosan (CS), carboxymethyl chitosan (CMC) and magnesium gluconate (MgG). Scaffolds were fabricated by subsequent freezing-induced phase separation and lyophilization of polyelectrolyte complexes of CS, CMC and MgG. The scaffolds possess uniform porosity with highly interconnected pores of 50–250 μm size range. Compressive strengths up to 400 kPa, and elastic moduli up to 5 MPa were obtained. The scaffolds were found to remain intact, retaining their original three-dimensional frameworks while testing in in-vitro conditions. These scaffolds exhibited no cytotoxicity to 3T3 fibroblast and osteoblast cells. These observations demonstrate the efficacy of this new approach to preparing scaffold materials suitable for tissue engineering applications.

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Chitosan-magnesium-based composite scaffolds successfully synthesized.

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Uniformly distributed 3D networks, stable in cell culture medium with pore size in the range of 50–250 μm obtained.

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Compressive strengths up to 400 kPa and elastic moduli up to 5 MPa obtained.

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No cytotoxicity observed with 3T3 fibroblast cells.

Biomimetic, Osteoconductive Non-mulberry Silk Fiber Reinforced Tricomposite Scaffolds for Bone Tissue Engineering

Composite biomaterials as artificial bone graft materials are pushing the present frontiers of bioengineering. In this study, a biomimetic, osteoconductive tricomposite scaffold made of hydroxyapatite (HA) embedded in non-mulberry Antheraea assama (A. assama) silk fibroin fibers and its fibroin solution is explored for its osteogenic potential. Scaffolds were physico-chemically characterized for morphology, porosity, secondary structure conformation, water retention ability, biodegradability, and mechanical property. The results revealed a ∼5-fold increase in scaffold compressive modulus on addition of HA and silk fibers to liquid silk as compared to pure silk scaffolds while maintaining high scaffold porosity (∼90%) with slower degradation rates. X-ray diffraction (XRD) results confirmed deposition of HA crystals on composite scaffolds. Furthermore, the crystallite size of HA within scaffolds was strongly regulated by the intrinsic physical cues of silk fibroin. Fourier transform infrared (FTIR) spectroscopy studies indicated strong interactions between HA and silk fibroin. The fabricated tricomposite scaffolds supported enhanced cellular viability and function (ALP activity) for both MG63 osteosarcoma and human bone marrow stem cells (hBMSCs) as compared to pure silk scaffolds without fiber or HA addition. In addition, higher expression of osteogenic gene markers such as collagen I (Col-I), osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP) further substantiated the applicability of HA composite silk scaffolds for bone related applications. Immunostaining studies confirmed localization of Col-I and BSP and were in agreement with real-time gene expression results. These findings demonstrate the osteogenic potential of developed biodegradable tricomposite scaffolds with the added advantage of the affordability of its components as bone graft substitute materials.

In situ synthesised TiO2-chitosan-chondroitin 4-sulphate nanocomposites for bone implant applications

The artificial materials for bone implant applications are gaining more importance in the recent years. The series titania-chitosan-chondroitin 4-sulphate nanocomposites of three different concentrations (2:1:x, where x- 0.125, 0.25, 0.5) have been synthesised by in situ sol-gel method and characterised by various techniques. The particle size of the nanocomposites ranges from 30-50 nm. The bioactivity, swelling nature, and the antimicrobial nature of the nanocomposites were investigated. The swelling ability and bioactivity of the composites is significantly greater and they possess high zone of inhibition against the microorganisms such as Staphylococcus aureus and Escherichia coli. The cell viability of the nanocomposites were evaluated by using MG-63 and observed the composites possess high cell viability at low concentration. The excellent bioactivity and biocompatibility makes these nanocomposites a promising biomaterial for bone implant applications.

The precision structural regulation of PLLA porous scaffold and its influence on the proliferation and differentiation of MC3T3-E1 cells

A thermal-induced phase separation combined sugar template method was used to fabricate the Poly (L-lactide) acid (PLLA) scaffolds with precisely regulated porous structure. The effect of tuned porous structure of scaffolds on osteoblasts proliferation and differentiation was investigated. The results showed that the pore diameters (200-300, 300-400, 400-500 μm), porosity and interconnectivity of PLLA scaffolds can be accurately controlled indicated by scanning electron microscope. The results of cell experiments showed that the porous structure including the pore size and interconnectivity of scaffolds dramatically influence the cell proliferation and differentiation. The scaffold with pore diameter of 400-500 μm exhibited the highest cell viability and alkaline phosphatase activity among all the scaffolds for the MC3T3-E1 cells. The higher cell proliferation and biocompatibility observed in the 400-500 μm scaffold indicated the high selectivity for MC3T3-E1cells on the pore size of scaffold in tissue engineering. The precise control of the porous structure of scaffold may better guide the cell-matrix interaction in the future research.

Bio-scaffolds produced from irradiated squid pen and crab chitosan with hydroxyapatite/β-tricalcium phosphate for bone-tissue engineering

In this study, bio-scaffolds have been developed using irradiated chitosan from different sources - squid pen (RS) and crab shell (RC) - with hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) at a chitosan/HA/β-TCP ratio of 50/30/20. The bio-scaffolds were prepared at two different freezing temperature (-20°C and -80°C) followed by lyophilisation. To enhance the mechanical properties, the bio-scaffolds were cross-linked using sodium tripolyphosphate (TPP) followed by lyophilisation. The composition and morphology of the bio-scaffolds were characterized using XRD, SEM, TEM and μ-CT. The pore size of the porous scaffolds ranged from 90 to 220μm and the scaffolds had 70-80% porosity. The scaffolds had a water uptake ratio of more than 10, and a controlled biodegradation in the range of 30-40%. These results suggest that the physical and biological properties of chitosan-based bio-scaffolds can be a promising biomaterial for bone-tissue regeneration.

An overview of chitin or chitosan/nano ceramic composite scaffolds for bone tissue engineering

Chitin and chitosan based nanocomposite scaffolds have been widely used for bone tissue engineering. These chitin and chitosan based scaffolds were reinforced with nanocomponents viz Hydroxyapatite (HAp), Bioglass ceramic (BGC), Silicon dioxide (SiO₂), Titanium dioxide (TiO₂) and Zirconium oxide (ZrO₂) to develop nanocomposite scaffolds. Plenty of works have been reported on the applications and characteristics of the nanoceramic composites however, compiling the work done in this field and presenting it in a single article is a thrust area. This review is written with an aim to fill this gap and focus on the preparations and applications of chitin or chitosan/nHAp, chitin or chitosan/nBGC, chitin or chitosan/nSiO₂, chitin or chitosan/nTiO₂ and chitin or chitosan/nZrO₂ in the field of bone tissue engineering in detail. Many reports so far exemplify the importance of ceramics in bone regeneration. The effect of nanoceramics over native ceramics in developing composites, its role in osteogenesis etc. are the gist of this review.

Chitosan based biocomposite scaffolds for bone tissue engineering

The clinical demand for scaffolds and the diversity of available polymers provide freedom in the fabrication of scaffolds to achieve successful progress in bone tissue engineering (BTE). Chitosan (CS) has drawn much of the attention in recent years for its use as graft material either as alone or in a combination with other materials in BTE. The scaffolds should possess a number of properties like porosity, biocompatibility, water retention, protein adsorption, mechanical strength, biomineralization and biodegradability suited for BTE applications. In this review, CS and its properties, and the role of CS along with other polymeric and ceramic materials as scaffolds for bone tissue repair applications are highlighted.

Development of functionalized multi-walled carbon nanotube-based polysaccharide–hydroxyapatite scaffolds for bone tissue engineering

fMWCNT–amylopectin–HAP and fMWCNT–gellan gum–HAP were prepared and characterized and their in vitro cell proliferation and ALP activity were checked for the first time.

Development of a new carbon nanotube-alginate-hydroxyapatite tricomponent composite scaffold for application in bone tissue engineering

In recent times, tricomponent scaffolds prepared from naturally occurring polysaccharides, hydroxyapatite, and reinforcing materials have been gaining increased attention in the field of bone tissue engineering. In the current work, a tricomponent scaffold with an oxidized multiwalled carbon nanotube (fMWCNT)-alginate-hydroxyapatite with the required porosity was prepared for the first time by a freeze-drying method and characterized using analytical techniques. The hydroxyapatite for the scaffold was isolated from chicken bones by thermal calcination at 800°C. The Fourier transform infrared spectra and X-ray diffraction data confirmed ionic interactions and formation of the fMWCNT-alginate-hydroxyapatite scaffold. Interconnected porosity with a pore size of 130-170 µm was evident from field emission scanning electron microscopy. The total porosity calculated using the liquid displacement method was found to be 93.85%. In vitro biocompatibility and cell proliferation on the scaffold was checked using an MG-63 cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cell attachment by Hoechst stain assay. In vitro studies showed better cell proliferation, cell differentiation, and cell attachment on the prepared scaffold. These results indicate that this scaffold could be a promising candidate for bone tissue engineering.

Biomedical potential of chitosan/HA and chitosan/β-1,3-glucan/HA biomaterials as scaffolds for bone regeneration--A comparative study

The aim of this work was to compare biomedical potential of chitosan/hydroxyapatite (chit/HA) and novel chitosan/β-1,3-glucan/hydroxyapatite (chit/glu/HA) materials as scaffolds for bone regeneration via characterization of their biocompatibility, porosity, mechanical properties, and water uptake behaviour. Biocompatibility of the scaffolds was assessed in direct-contact with the materials using normal human foetal osteoblast cell line. Cytotoxicity and osteoblast proliferation rate were evaluated. Porosity was assessed using computed microtomography analysis and mechanical properties were determined by compression testing. Obtained results demonstrated that chit/HA scaffold possessed significantly better mechanical properties (compressive strength: 1.23 MPa, Young's modulus: 0.46 MPa) than chit/glu/HA material (compressive strength: 0.26 MPa, Young's modulus: 0.25 MPa). However, addition of bacterial β-1,3-glucan to the chit/HA scaffold improved its flexibility and porosity. Moreover, chit/glu/HA scaffold revealed significantly higher water uptake capability (52.6% after 24h of soaking) compared to the chit/HA (30.7%) and thus can serve as a very good drug delivery carrier. Chit/glu/HA scaffold was also more favourable to osteoblast survival (near 100% viability after 24-h culture), proliferation, and spreading compared to the chit/HA (63% viability). The chit/glu/HA possesses better biomedical potential than chit/HA scaffold. Nevertheless, poor mechanical properties of the chit/glu/HA limit its application to non-load bearing implantation area.

Development and characterization of hydroxyapatite/β-TCP/chitosan composites for tissue engineering applications

Calcium phosphate ceramics that mimic bone composition provide interesting possibilities for the advancement in bone tissue engineering. The present study reports on a chitosan composite reinforced by hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) obtained from waste mussel shells and cross-linked using tripolyphosphate (TPP). The ratios of the ceramic components in composites were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/CH, w/w %). Biodegradation rate, structural properties and in-vitro degradation of the bone-like composite scaffolds were investigated. The optimum amount of TPP required for composite was 2.5% and glycerol was used as plasticizer at an optimized concentration of 1%. Tripolyphosphate cross-linked chitosan composites were developed by freezing and lyophilisation. The Young's modulus of the scaffolds was increased from 4kPa to 17kPa and the porosity of composites dropped from 85 to 68% by increasing the HA/β-TCP ratio. After 28days in physiological solution, bone-like composite scaffolds with a higher ratio of HA/β-TCP (e.g. 40/30/30) showed about 2% lower biodegradation in comparison to scaffolds with a lower ratio of HA/β-TCP (i.e. 20/10/70). The obtained data suggest that the chitosan based bone-like composites could be potential candidates for biomedical applications.

PVA-chitosan composite hydrogel versus alginate beads as a potential mesenchymal stem cell carrier for the treatment of focal cartilage defects

PURPOSE

To investigate whether mesenchymal stem cells (MSCs) seeded in novel polyvinyl alcohol (PVA)-chitosan composite hydrogel can provide comparable or even further improve cartilage repair outcomes as compared to previously established alginate-transplanted models.

METHODS

Medial femoral condyle defect was created in both knees of twenty-four mature New Zealand white rabbits, and the animals were divided into four groups containing six animals each. After 3 weeks, the right knees were transplanted with PVA-chitosan-MSC, PVA-chitosan scaffold alone, alginate-MSC construct or alginate alone. The left knee was kept as untreated control. Animals were killed at the end of 6 months after transplantation, and the cartilage repair was assessed through Brittberg morphological score, histological grading by O'Driscoll score and quantitative glycosaminoglycan analysis.

RESULTS

Morphological and histological analyses showed significant (p < 0.05) tissue repair when treated with PVA-chitosan-MSC or alginate MSC as compared to the scaffold only and untreated control. In addition, safranin O staining and the glycosaminoglycan (GAG) content were significantly higher (p < 0.05) in MSC treatment groups than in scaffold-only or untreated control group. No significant difference was observed between the PVA-chitosan-MSC- and alginate-MSC-treated groups.

CONCLUSION

PVA-chitosan hydrogel seeded with mesenchymal stem cells provides comparable treatment outcomes to that of previously established alginate-MSC construct implantation. This study supports the potential use of PVA-chitosan hydrogel seeded with MSCs for clinical use in cartilage repair such as traumatic injuries.

Enhanced differentiation of osteoblastic cells on novel chitosan/β-1,3-glucan/bioceramic scaffolds for bone tissue regeneration

Bone scaffolds for regenerative medicine applications should have the ability to promote adhesion, proliferation and differentiation of osteoblast cells. Osteoconductive, osteoinductive and osteopromotive properties of the material are essential for rapid bone regeneration and new bone formation. In this study, the osteogenic potential of two novel tri-component scaffolds composed of krill chitosan, bacterial β-1,3-glucan and bioceramics (HAp or a mix of HAp/β-TCP granules) was investigated. The typical markers of the first (type I collagen), second (bone alkaline phosphatase) and third stages (osteocalcin) of the osteoblast differentiation process were evaluated during in vitro experimentation. The study was carried out using three various osteoblastic cell lines (normal human fetal osteoblast cells hFOB 1.19, human osteoblast-like cells derived from osteosarcoma Saos-2 and mouse calvarial preosteoblast cells MC3T3-E1 Subclone 4). The bone alkaline phosphatase (bALP) and osteocalcin (OC) were determined quantitatively using enzyme-linked immunosorbent assays, and type I collagen (Col I) was evaluated qualitatively using the direct immunofluorescence (DIF) method. The data obtained clearly prove that novel scaffolds have the ability to increase bALP activity, to enhance extracellular matrix synthesis (Col I and OC) and to induce mineralized nodule formation during osteogenic differentiation. In conclusion, novel tri-component materials have osteoconductive and osteopromotive properties, and thus are promising materials in bone tissue engineering applications to accelerate the bone regeneration process.

Development of new graphene oxide incorporated tricomponent scaffolds with polysaccharides and hydroxyapatite and study of their osteoconductivity on MG-63 cell line for bone tissue engineering

GO–alginate–HAP, GO–amylopectin–HAP and GO–gellan gum–HAP were prepared and characterized and their osteoconductivity were checked for the first time.

Addition of 1,3-β-D-glucan to chitosan-based composites enhances osteoblast adhesion, growth, and proliferation

The aim of this work was to prove using two osteoblastic cell lines that addition of bacterial 1,3-β-D-glucan to chitosan-based biocomposites significantly enhances adhesion, growth, and proliferation of osteoblast cells. Cytotoxicity of materials was evaluated indirectly using fluid extracts and by direct-contact method using live/dead double fluorescent staining. Cell adhesion was determined quantitatively by LDH total test and cell proliferation was assessed by confocal microscope observation. Obtained data clearly prove that addition of 1,3-β-D-glucan to the bi-component chitosan/bioceramic materials significantly enhances adhesion, growth, and proliferation of osteoblast cells. The results demonstrated that all investigated biomaterials were non-toxic and allowed for cell attachment. However, significantly better osteoblast growth was observed on scaffolds containing 1,3-β-D-glucan. Thus, it may be inferred that scaffolds modified with glucan are more promising materials for bone tissue engineering application than bi-component chitosan/bioceramic composites.

Multifunctional materials for bone cancer treatment

The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies.

Chitosan/β-1,3-glucan/calcium phosphate ceramics composites--novel cell scaffolds for bone tissue engineering application

Bone tissue engineering put emphasis on fabrication three-dimensional biodegradable porous scaffolds that possess ability to enhance adhesion, proliferation and differentiation of osteoblast cells, therefore supporting bone regeneration and functional bone tissue formation. The aim of this work was to fabricate novel tri-component scaffolds composed of chitosan, β-1,3-glucan, and bioceramics and to evaluate their basic structural, mechanical, and biological properties. It should be noted that we are the first who describe fabrication and characterization of tri-component composites containing β-1,3-glucan. Microstructure of novel composites was visualized by computed tomography scanning and SEM. Compressive strength and Young's modulus of the composites were evaluated by compression testing. The biocompatibility was assessed in vitro by cytotoxicity, cell attachment and cell proliferation tests using human foetal osteoblast cell line. Our results demonstrated that novel composites possess good compressive strength as the effect of polysaccharide components of scaffolds, are very elastic, are non-toxic, favourable to cell adhesion and promote cell proliferation. However, novel biomaterials revealed relatively low Young's modulus values. Thus, we infer that fabricated novel composites are promising materials for bone tissue engineering application as cell scaffolds to fill small bone losses rather than as massive bone fillers exposed to mechanical load.

Chitosan-alginate biocomposite containing fucoidan for bone tissue engineering

Over the last few years, significant research has been conducted in the construction of artificial bone scaffolds. In the present study, different types of polymer scaffolds, such as chitosan-alginate (Chi-Alg) and chitosan-alginate with fucoidan (Chi-Alg-fucoidan), were developed by a freeze-drying method, and each was characterized as a bone graft substitute. The porosity, water uptake and retention ability of the prepared scaffolds showed similar efficacy. The pore size of the Chi-Alg and Chi-Alg-fucoidan scaffolds were measured from scanning electron microscopy and found to be 62–490 and 56–437 µm, respectively. In vitro studies using the MG-63 cell line revealed profound cytocompatibility, increased cell proliferation and enhanced alkaline phosphatase secretion in the Chi-Alg-fucoidan scaffold compared to the Chi-Alg scaffold. Further, protein adsorption and mineralization were about two times greater in the Chi-Alg-fucoidan scaffold than the Chi-Alg scaffold. Hence, we suggest that Chi-Alg-fucoidan will be a promising biomaterial for bone tissue regeneration.

Emerging nanostructured materials for musculoskeletal tissue engineering

This review summarizes the recent developments in the preparation and applications of nanostructured materials for musculoskeletal tissue engineering.

Mesoporous bioactive glass as a drug delivery system: fabrication, bactericidal properties and biocompatibility

Implant-associated infection remains a difficult medical problem in orthopaedic surgery. Here, we report on the fabrication of gentamicin-loaded mesoporous bioactive glass (Gent-MBG) for use as a controlled antibiotic delivery system to achieve the sustained release of antibiotics in the local sites of bone defects. The high surface area and mesoporous structure of MBG enable higher drug loading efficiency (79-83 %) than non-mesoporous biological glass (NBG) (18-19 %). Gent-MBG exhibits sustained drug release for more than 6 days, and this controlled release of gentamicin significantly inhibits bacterial adhesion and prevents biofilm formation by S. aureus (ATCC25923) and S. epidermidis (ATCC35984). Biocompatibility tests with human bone marrow stromal cells (hBMSCs) indicate that MBG has better biocompatibility than NBG. Therefore, Gent-MBG can be used as a controlled drug delivery system to prevent and/or treat orthopedic peri-implant infections.

Nanocomposites for bone tissue regeneration

Natural bone tissue possesses a nanocomposite structure that provides appropriate physical and biological properties. For bone tissue regeneration, it is crucial for the biomaterial to mimic living bone tissue. Since no single type of material is able to mimic the composition, structure and properties of native bone, nanocomposites are the best choice for bone tissue regeneration as they can provide the appropriate matrix environment, integrate desirable biological properties, and provide controlled, sequential delivery of multiple growth factors for the different stages of bone tissue regeneration. This article reviews the composition, structure and properties of advanced nanocomposites for bone tissue regeneration. It covers aspects of interest such as the biomimetic synthesis of bone-like nanocomposites, guided bone regeneration from inert biomaterials and bioactive nanocomposites, and nanocomposite scaffolds for bone tissue regeneration. The design, fabrication, and in vitro and in vivo characterization of such nanocomposites are reviewed.