Development of a novel glucosamine/silk fibroin–chitosan blend porous scaffold for cartilage tissue engineering applications

Silk-Based 3D Porous Scaffolds for Tissue Engineering

Silk fibroin, extracted from the silk of the Bombyx mori silkworm, stands out as a biomaterial due to its nontoxic nature, excellent biocompatibility, and adjustable biodegradability. Porous scaffolds, a type of biomaterial, are crucial for creating an optimal microenvironment that supports cell adhesion and proliferation, thereby playing an essential role in tissue remodeling and repair. Therefore, this review focuses on 3D porous silk fibroin-based scaffolds, first summarizing their preparation methods and then detailing their regenerative effects on bone, cartilage, tendon, vascular, neural, skin, hepatic, and tracheal epithelial tissue engineering in recent years.

Fabrication and assessment of a novel hybrid scaffold consisted of polyurethane-gellan gum-hyaluronic acid-glucosamine for meniscus tissue engineering

The meniscus has inadequate intrinsic regenerative capacity and its damage can lead to degeneration of articular cartilage. Meniscus tissue engineering aims to restore an injured meniscus followed by returning its normal function through bioengineered scaffolds. In the present study, the structural and biological properties of 3D-printed polyurethane (PU) scaffolds dip-coated with gellan gum (GG), hyaluronic acid (HA), and glucosamine (GA) were investigated. The optimum concentration of GG was 3% (w/v) with maintaining porosity at 88.1%. The surface coating of GG-HA-GA onto the PU scaffolds increased the compression modulus from 30.30 kPa to 59.10 kPa, the water uptake ratio from 27.33% to 60.80%, degradation rate from 5.18% to 8.84%, whereas the contact angle was reduced from 104.8° to 59.3°. MTT assay, acridine orange/ethidium bromide (AO/EB) fluorescent staining, and SEM were adopted to assess the behavior of the seeded chondrocytes on scaffolds, and it was found that the ternary surface coating stimulated the cell proliferation, viability, and adhesion. Moreover, the coated scaffolds showed higher expression levels of collagen II and aggrecan genes at day 7 compared to the control groups. Therefore, the fabricated PU-3% (w/v) GG-HA-GA scaffold can be considered as a promising scaffold for meniscus tissue engineering.

Nanofibrillated cellulose/glucosamine 3D aerogel implants loaded with rosuvastatin and bioactive ceramic for dental socket preservation

Recycling of agro-wastes presents a great economic and ecologic value. In this study, TEMPO-oxidized nanofibrillated cellulose (TONFC) originating from sugarcane bagasse pulp was exploited in regenerative medicine. TONFC in combination with glucosamine HCl (G) were used to prepare a 3D aerogel implant loaded with rosuvastatin as an integrative approach for extraction-socket healing. Comparing the prepared devices, aerogel composed of TONFC: G (4:1 wt ratio) had the best mechanical properties and integrity. Strontium borate-based bioactive ceramic particles were prepared and characterized for crystal structure, shape, porosity, and zeta potential. The particles had a crystalline diffraction pattern relative to Sr₃B₂O₆, and they were rod in shape with nanopores with a zeta potential value of -16 mV. The prepared bioactive ceramic (BC) was then added in different concentrations (3 or 6% w/w) to the selected aerogel implant. The BC had a concentration-dependent effect on the aerogel properties as it ameliorated its mechanical performance (compressive strength = 90 and 150 kPa for 3 and 6%, respectively) and retarded drug release (mean release time = 2.34 and 3.4 h for 3 and 6%, respectively) (p < 0.05). The microphotograph of the selected aerogel implant loaded with BC showed a rough surface with an interconnective porous structure. During cell biology testing, the selected implant loaded with the lower BC concentration had the highest ability to increase MG-63 cells proliferation. In conclusion, TONFC is a promising material to formulate rosuvastatin-loaded aerogel implant with the aid of glucosamine and bioactive ceramic for dental socket preservation.

Terrestrial insects as a promising source of chitosan and recent developments in its application for various industries

Chitosan is a deacetylated form of chitin and increasingly important amino-polysaccharide used in many various sectors including agriculture, food, and biomedicine. However, chitosan from marine sources has several adverse effects, including allergenic components harmful to human health. Furthermore, marine resources are seasonal, and availability is limited due to dependency on environmental conditions and climate change. In addition, shell infection in crustaceans and environmental contamination make the harvesting of chitin and chitosan problematic. In recent years, chitosan from terrestrial insects has attracted considerable interest. The discoveries show insect chitosan is more advantageous compared to crustacean chitosan. In addition, we were unable to find any literature about the adverse effects of insect chitosan thus far. This review aims to reveal information regarding crustacean and terrestrial insect chitosan and recent advances in chitosan sources. Applications from specific insect orders and perspectives for further study will also be highlighted, including medical and sensing applications.

Cartilage tissue engineering using injectable functionalized Demineralized Bone Matrix scaffold with glucosamine in PVA carrier, cultured in microbioreactor prior to study in rabbit model

Using 3D model of injectable scaffolds for cartilage tissue engineering is one of the challenges that should be addressed to avoid invasive surgery for treatment. For this purpose, chondrocytes on Demineralized Bone Matrix (DBM) scaffolds functionalized with glucosamine in 20% polyvinyl alcohol (PVA) as a carrier was applied to the micro-bioreactor in-vitro, then the study was continued on in-vivo stage. Scaffold biocompatibility tests were performed and the mechanical and physicochemical properties were studied showing the fact that DBM was functionalized by Glucosamine, scaffold degradation rate was 53% after 720 h and swelling ratio was 2.5 times after 16 h, injectable scaffold demonstrated better mechanical characteristics (P < 0.05) than other concentrations of PVA. Consequently, in-vitro tests, including live-dead imaging resulting in 99% viability after 14 days (P < 0.001), DAPI staining and scanning electron microscope imaging were performed to determine the number and viability of the cells on the scaffold, showing a cells proliferation property of this group compared with the control after 14 days (P < 0.0001), then relative gene expression was evaluated and protein expression was assessed. The overall chondrogenic gene expression improved (P < 0.05) compared to the control (2D culture). Subsequently, the scaffold were loaded with chondrocytes and injected into the cartilage lesion part After 24 weeks of surgery, MRI and immunocytochemistry were performed. Then all outputs proved that the scaffold plus cell group had a significantly higher topological score (P < 0.0001) than other groups compared to normal cartilage. Finally, studies have shown that transplantation of chondrocytes in DBM, polyvinyl alcohol and glucosamine scaffold through one surgical stage improves cartilage lesion and it can be considered as a breakthrough in tissue engineering.

Fabrication and in-vitro biocompatibility of freeze-dried CTS-nHA and CTS-nBG scaffolds for bone regeneration applications

The thought of biodegradable organic-inorganic composites composed of natural polymer chitosan and ceramic nanoparticles (hydroxyapatite and bioglass) can be considered as a solution for hard tissue engineering. In this paper, we described a comparative assessment of chitosan-nanohydroxyapatite (CTS-nHA) and chitosan-nano-bioglass (CTS-nBG) scaffolds. The dispersion of nanoscaled hydroxyapatite (nHA) and bioglass (nBG) in chitosan remained satisfactory. The freeze-dried composite based CTS-nHA and CTS-nBG scaffolds shown porous structure. The physiochemical and morphological analysis of all samples has been performed through X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The SEM image confirmed the presence of spherically shaped nHA particles of 4.20 μm and irregularly shaped nBG particles of 6.89 μm. The TEM analysis revealed the existence of 165.52 to 255.17 nm sized nHA particles and 167.35 to 334.69 nm sized nBG particles. TEM analysis also showed the interconnected structure of CTS-nHA and CTS-nBG nanocomposites. After seven days' incubation period, the CTS-nHA and CTS-nBG scaffolds shown good mineralization behavior in simulated body fluid (SBF). The CTS-nHA scaffolds exhibited enhanced compressive strength and elastic modulus compared with the CTS-nBG sample. The cell culture experiment revealed that fabricated scaffolds had good compatibility with fibroblast cells (L929, ATCC) and MG-63 which are able to adhere, proliferate, and migrate through the porous structure. All the obtained results clearly recommend that pre-loaded hydroxyapatite and bioglass nanoparticles can enhance the apatite formation. The scaffolds with chitosan, bioglass, and hydroxyapatite have better biomechanical characteristics and allow cell growth. Therefore, these scaffolds can be perfect candidates for various hard tissue engineering applications such as bone regeneration.

Hybrid and Composite Scaffolds Based on Extracellular Matrices for Cartilage Tissue Engineering

IMPACT STATEMENT

Scaffolds fabricated from extracellular matrix (ECM) derivatives are composed of conducive structures for cell attachment, proliferation, and differentiation, but generally do not have proper mechanical properties and load-bearing capacity. In contrast, scaffolds based on synthetic biomaterials demonstrate appropriate mechanical strength, but the absence of desirable biological properties is one of their main disadvantages. To integrate mechanical strength and biological cues, these ECM derivatives can be conjugated with synthetic biomaterials. Hence, hybrid scaffolds comprising both advantages of synthetic polymers and ECM derivatives can be considered a robust vehicle for tissue engineering applications.

Enhanced chondrogenic differentiation of human mesenchymal stem cells in silk fibroin/chitosan/glycosaminoglycan scaffolds under dynamic culture condition

Cartilage tissue damage and diseases are the most common clinical situation that occurs because of aging and injury, thereby causing pain and loss of mobility. The inability of cartilage tissue to self-repair is instrumental in developing tissue engineered substitutes. To this effect, the present study aims to engineer cartilage construct by culturing umbilical cord blood-derived human mesenchymal stem cells (hMSCs) on novel 3D porous scaffolds developed from natural biopolymers, silk fibroin (SF) and chitosan (CS), with addition of cartilage matrix components, glucosamine (Gl) and chondroitin sulfate (Ch). The presence of Gl and Ch is expected to enhance cartilage regeneration. The developed SF/CS-Gl-Ch scaffolds possess desired pore size in the range 56.55-168.15 μm, 88-92% porosity, 44.7-46.8̊ contact angle, controlled swelling and biodegradability. Upon culturing under dynamic condition in a spinner flask bioreactor, the scaffold supported hMSCs attachment, proliferation, and further promoted chondrogenic differentiation. Cartilage-specific matrix and gene (Collagen II, Sox9 and aggrecan) expression analyses by histology, immunophenotype, immunofluorescence and quantitative PCR studies showed superiority of cell-scaffold construct generated in dynamic culture towards cartilage tissue generation as compared to cell aggregates formed by pellet culture. This study demonstrates the potentiality of SF/CS-Gl-Ch porous scaffold for the development of tissue construct for cartilage regeneration under dynamic culture condition.

Fabrication and evaluation of non-mulberry silk fibroin fiber reinforced chitosan based porous composite scaffold for cartilage tissue engineering

Lack of potential regenerative medicine to reconstruct damaged cartilage tissue has accelerated investigation and development of potential biomaterial for cartilage tissue engineering. In this study, we fabricated micron-sized non-mulberry silk fibroin fiber (SFF) using N,N-Dimethylacetamide (DMA_C)/10% LiBr solution and further used to develop SFF reinforced chitosan(CH) based porous scaffold with desired pore size, porosity, swelling and structural stability. The developed scaffold was characterized for its various physico-chemical, mechanical and biological properties. The developed CH/SFF composite scaffold facilitates human mesenchymal stem cell (hMSCs) attachment, colonization and extracellular matrix deposition. Furthermore, hMSCs shows significantly higher sulfated glycosaminoglycan deposition over CH/SFF in comparison to pure chitosan scaffold (control). Immunocytochemistry studies have shown enhanced expression of collagen type II and aggrecan by hMSCs over composite scaffold than chitosan scaffold. Thus, non-mulberry silk fibroin fiber reinforced chitosan based scaffold might be suitable scaffold that can act as a potential artificial matrix for cartilage tissue engineering.

Chondrogenic differentiation of mesenchymal stem cells on silk fibroin:chitosan–glucosamine scaffold in dynamic culture

Aim: Cartilage damage is a common age-related problem that leads to progressive proteoglycan loss. Glucosamine stimulates proteoglycan synthesis and, therefore, its effect on the cartilage extracellular matrix synthesis over silk fibroin:chitosan (SF:CS) tissue-engineered scaffold was investigated for cartilage construct generation. Materials & methods: Human mesenchymal stem cells (hMSCs) were cultured and differentiated over SF:CS–glucosamine porous scaffold, under dynamic culture condition in spinner flask bioreactor. Results: hMSCs-seeded scaffold in dynamic culture exhibited homogenous cell distribution, proliferation and higher cell density at the core than static culture. Glucosamine in scaffold promoted proteoglycan and collagenous matrix synthesis as revealed by histological and immunofluorescence studies. Quantitative-PCR analysis showed upregulation of cartilage-specific genes, thereby confirming the chondrogenic differentiation. Conclusion: The chondrogenic differentiation of hMSCs was enhanced by the synergistic effect of glucosamine incorporated in SF:CS scaffold and influence of 3D dynamic culture environment, thereby resulting in chondrogenic phenotype of the cells that promoted cartilage regeneration.

Protein-Based Fiber Materials in Medicine: A Review

Fibrous materials have garnered much interest in the field of biomedical engineering due to their high surface-area-to-volume ratio, porosity, and tunability. Specifically, in the field of tissue engineering, fiber meshes have been used to create biomimetic nanostructures that allow for cell attachment, migration, and proliferation, to promote tissue regeneration and wound healing, as well as controllable drug delivery. In addition to the properties of conventional, synthetic polymer fibers, fibers made from natural polymers, such as proteins, can exhibit enhanced biocompatibility, bioactivity, and biodegradability. Of these proteins, keratin, collagen, silk, elastin, zein, and soy are some the most common used in fiber fabrication. The specific capabilities of these materials have been shown to vary based on their physical properties, as well as their fabrication method. To date, such fabrication methods include electrospinning, wet/dry jet spinning, dry spinning, centrifugal spinning, solution blowing, self-assembly, phase separation, and drawing. This review serves to provide a basic knowledge of these commonly utilized proteins and methods, as well as the fabricated fibers’ applications in biomedical research.