IIT Hyderabad Researchers Develop Collagen From Waste Eel Skin

Indian Institute of Technology (IIT) Hyderabad Researchers have derived collagen from waste eel skin and shown that tissue scaffolds built using such collagen allow growth and proliferation of stem cells

Valorization of discarded Marine Eel fish skin for collagen extraction as a 3D printable blue biomaterial for tissue engineering

Discarded marine Eel fish skin has essential properties of biomaterials for potential use in tissue engineering application. Processing and preparation of eel fish for edible purpose requires the removal of skin due to its thick size, which is treated as a waste. A huge amount of Eel skin is dumped as a waste material which leads to marine environmental pollution. To overcome this issue, we have isolated collagen from the discarded marine Eel skin as a potential blue biomaterial. Further, the isolated collagen was incorporated into alginate hydrogel to fabricate scaffolds using extrusion-based 3D printing technology. Swelling, degradation and biocompatibility were evaluated for lyophilized scaffolds. Biocompatibility studies were performed on hUMSCs (Human Umbilical cord Derived Mesenchymal Stem Cells) by live/dead staining using FDA (fluorescein diacetate)/PI (Propidium Iodide). The quantitative evaluation of metabolic activity was performed using Alamar Blue (AB) dye reduction assay. All the hydrogels with collagen show enhanced metabolic activity and cell proliferation compared to alginate hydrogels without collagen. The utilization of Eel skin derived collagen for 3D printing application was not yet reported. Moreover, sustainable utilization of renewable marine Eel skin discard as a novel blue biomaterial is of immense value due to its low cost and has great potential for further tissue engineering applications

3D printable SiO2 nanoparticle ink for patient specific bone regeneration

Sodium alginate and gelatin are biocompatible & biodegradable natural polymer hydrogels, which are widely investigated for application in tissue engineering using 3D printing and 3D bioprinting fabrication techniques. The major challenge of using hydrogels for tissue fabrication is their lack of regeneration ability, uncontrolled swelling, degradation and inability to hold 3D structure on their own. Free hydroxyl groups on the surface of SiO2 nanoparticles have the ability to chemically interact with alginate–gelatin polymer network, which can be explored to achieve the above parameters. Hence validating the incorporation of SiO2 nanoparticles in a 3D printable hydrogel polymer network, according to the patient's critical defects has immense scope in bone tissue engineering. In this study, SiO2 nanoparticles are loaded into alginate–gelatin composite hydrogels and chemically crosslinked with CaCl2 solution. The effect of SiO2 nanoparticles on the viscosity, swelling, degradation, compressive modulus (MPa), biocompatibility and osteogenic ability were evaluated on lyophilized scaffolds and found to be desirable for bone tissue engineering. A complex irregular patient-specific virtual defect was created and the 3D printing process to fabricate such structures was evaluated. The 3D printing of SiO2 nanoparticle hydrogel composite ink to fabricate a bone graft using a patient-specific virtual defect was successfully validated. Hence this type of hydrogel composite ink has huge potential and scope for its application in tissue engineering and nanomedicine

Mechanochemically synthesized phase stable and biocompatible β-tricalcium phosphate from avian eggshell for the development of tissue ingrowth system

Bioceramics obtained from naturally derived materials are gaining much interest as implants for bone and dental defects. The present study aims to synthesize phase stable β-tricalcium phosphate (β-TCP) from avian eggshell assisted with ball milling process followed by a wet chemical precipitation method (Group CPM). The effect of mechanical stimulation on phase conversion of CaO was also studied. The study was carried alongside the powders synthesized from chemical precursors (Group CPS) as well as eggshell derived powders without ball milling process (Group CPN). The phase behaviour and surface morphology were studied by XRD, FT-IR, and SEM analysis. Scaffolds were fabricated using sponge replication method to simulate a potential bone graft analogue. The cytocompatibility study was performed by human adipose-derived stem cells (ADSCs) over a period of 21 days by live-dead assay and Alamar blue dye reduction assay. The process of mechanically stimulating CaO precursor through extensive milling plays a major role on phase stabilization of β-TCP, as compared to the mixed phases of Hydroxyapatite (HAp) and β-TCP formed from unmilled CaO. Group CPN scaffolds were found to be biologically equivalent to group CPS scaffolds. This novel route, aided with ball-milling process for the synthesis of β-TCP from naturally occurring eggshell waste seems promising enough to replace commercially available β-TCP produced from harmful nitrate precursors and has the capability to develop implantable biomaterial for tissue regeneration

Sodium alginate/gelatin with silica nanoparticles a novel hydrogel for 3D printing

Sodium alginate/gelatin hydrogels are promising materials for 3D bio-printing due to its good biocompatibility and biodegradability. Gelatin is used for thermal crosslinking and its cell adhesion properties. Hence patient specific sodium alginate/gelatin hydrogel scaffolds can be bio-fabricated in a temperature range of 4-14 oC. In this study we made an attempt to introduce silica (SiO2) nanoparticles in the polymer network of sodium alginate (2.5%)/gelatin (8%) hydrogel at different concentrations (w/v) as 0%, 1.25%, 2.5%, 5%, and 7.5%. The effect of silica nanoparticles on viscosity, swelling behavior, and degradation rate are analyzed. Hydrogels with 5% silica nanoparticles show significantly less swelling and degradation when compared to other concentrations. The viscosity of the hydrogels gradually increases up to 5% addition of silica nanoparticles enhancing the stability of 3D printed structures

Modulation of 3D Printed Calcium-Deficient Apatite Constructs with Varying Mn Concentrations for Osteochondral Regeneration via Endochondral Differentiation

Osteochondral regeneration remains a vital problem in clinical situations affecting both bone and cartilage tissues due to the low regeneration ability of cartilage tissue. Additionally, the simultaneous regeneration of bone and cartilage is difficult to attain due to their dissimilar nature. Thus, fabricating a single scaffold for both bone and cartilage regeneration remains challenging. Biomaterials are frequently employed to promote tissue restoration, but they still cannot replicate the structure of native tissue. This study aims to create a single biomaterial that could be used to regenerate both bone and cartilage. This study focuses on synthesizing calcium-deficient apatite (CDA) with the gradual addition of manganese. The phase stability and the effect of heat treatment on manganese-doped CDA were studied using X-ray diffraction (XRD) and Rietveld refinement. The obtained powders were tested for their 3-dimensional (3D) printing ability by fabricating cuboidal 3D structures. The 3D printed scaffolds were examined for external topography using field-emission scanning electron microscopy (FE-SEM) and were subjected to compression testing. In vitro biocompatibility and differentiation studies were performed to access their biocompatibility and differentiation capabilities. Reverse transcription-quantitative PCR (RT-qPCR) analysis was done to determine the gene expression of bone-and cartilage-specific markers. Mn helps in stabilizing the β-TCP phase beyond its sintering temperature without being degraded to α-TCP. Mn addition in CDA improves the compressive strength of the fabricated scaffolds while keeping them biocompatible. The concentrations of Mn in the CDA ceramic were found to influence the differentiation behavior of MSCs in the fabricated scaffolds. Mn-doped CDA is a promising candidate to be used as a substitute material for bone, cartilage, and osteochondral defects to facilitate repair and regeneration via endochondral differentiation. 3D printing can assist in the fabrication of a multifunctional single-unit scaffold with varied Mn concentrations, which might be able to generate the two tissues in situ in an osteochondral defect. © 2022 American Chemical Society

Optimization of extrusion based ceramic 3D printing process for complex bony designs

In this study presents materials and design optimization of clinically approved hydroxyapatite (HA) using extrusion based 3D printing process. The effect of various printing parameters including print speed, extrusion pressure, accuracy and infill density to produce defined porous structures is established using various techniques. Particularly Scanning Electron Microscopy, Micro Computed Tomography have been employed to study internal and external accuracy. Mechanical testing was employed to study the effect of porosity on compressive properties of 3D printed structures. This study shows that, the infill density and shrinkage of 3D printed HA scaffolds post sintering have a linear relationship. Porosity and mechanical strength of 3D printed scaffolds depend on the infill density of the designed CAD file. Tailoring infill density also helps in altering mechanical properties in a predictable manner. Finally, a case study on hydroxyapatite printing of a patient specific bone graft demonstrates the ability of this material and technique to print complex porous structures created on CT-based anatomical bone models and pre-operative 3D planning, providing further promise for custom implant development for complex bony designs

Optimization of extrusion based ceramic 3D printing process for complex bony designs

In this study presents materials and design optimization of clinically approved hydroxyapatite (HA) using extrusion based 3D printing process. The effect of various printing parameters including print speed, extrusion pressure, accuracy and infill density to produce defined porous structures is established using various techniques. Particularly Scanning Electron Microscopy, Micro Computed Tomography have been employed to study internal and external accuracy. Mechanical testing was employed to study the effect of porosity on compressive properties of 3D printed structures. This study shows that, the infill density and shrinkage of 3D printed HA scaffolds post sintering have a linear relationship. Porosity and mechanical strength of 3D printed scaffolds depend on the infill density of the designed CAD file. Tailoring infill density also helps in altering mechanical properties in a predictable manner. Finally, a case study on hydroxyapatite printing of a patient specific bone graft demonstrates the ability of this material and technique to print complex porous structures created on CT-based anatomical bone models and pre-operative 3D planning, providing further promise for custom implant development for complex bony designs