Jahid M. M. Islam

Fabrication and characterization of gelatin-based biocompatible porous composite scaffold for bone tissue engineering †

In this study, composite scaffolds were prepared with polyethylene oxide (PEO)-linked gelatin and tricalcium phosphate (TCP). Chitosan, a positively charged polysaccharide, was introduced into the scaffolds to improve the properties of the artificial bone matrix. The chemical and thermal properties of composite scaffolds were investigated by Fourier transform infrared spectroscopy, thermogravimetric analyzer, differential thermal analyzer. In vitro cytotoxicity of the composite scaffold was also evaluated and the sample showed no cytotoxic effect. The morphology was studied by SEM and light microscopy. It was observed that the prepared scaffold had an open interconnected porous structure with pore size of 230-354 μm, which is suitable for osteoblast cell proliferation. The mechanical properties were assessed and it was found that the composite had compressive modulus of 1200 MPa with a strength of 5.2 MPa and bending modulus of 250 MPa having strength of 12.3 MPa. The porosity and apparent density were calculated and it was found that the incorporation of TCP can reduce the porosity and water absorption. It was revealed from the study that the composite had a 3D porous microstructure and TCP particles were dispersed evenly among the crosslinked gelatin/chitosan scaffold.

Physico-mechanical properties of wound dressing material and its biomedical application.

A bioadhesive wound dressing material, based on gelatin, was prepared by solution casting, and its properties were evaluated. The tensile strength (TS) and percentage elongation at break (Eb) of the membranes were found to be 12.7 MPa and 40.4%, respectively. The buffer uptake and water uptake of the prepared membranes were found to be 298 and 312%, respectively, after 8 min. A scanning electron micrograph of the membrane revealed its uniform porosity, which is an essential criterion to be an ideal wound dressing. From microbial sensitivity analysis, it was found that the membrane had a significant resistance against infection. The wound-healing characteristics of the membrane were evaluated using a rat (Rattus norvegicus) model. Full-thickness wounds were created on the ventral side of the Rattus norvegicus and were dressed with the membrane; eco-plast was used as a control. The wound healing and bioadhesion were monitored at 3-day intervals by real-time imaging. The results revealed that the prepared membrane was more effective in healing the wound than conventional wound dressing.

Preparation and Characterization of Starch/PVA Blend for Biodegradable Packaging Material

Polymer films of rice starch/Polyvinyl alcohol (PVA) were prepared by casting method. Different blends were made varying the concentration of rice starch and PVA. Tensile strength (TS) and elongation at break (Eb) of the prepared films were studied. Films made up of rice starch and PVA with a ratio of 2:8 showed highest TS. 10% sugar was added with highest TS giving four composition of Starch/PVA blend in order to increase TS and Eb. Films made up of rice starch and PVA and sugar with a ratio of 1:8:1 showed highest TS and Eb and the recorded value was 14.96MPa and 637% respectively. The physico-mechanical properties of the prepared sugar incorporated films were improved by grafting with acrylic monomer with the aid of UV radiation. A formulation was prepared with monomer, methylmethacrylat in methanol, and a photo initiator. The highest TS of the grafted films were recorded and the value was 16.38 MPa. The water uptake and weight loss in both soil and water of the grafted films are lower than the non-grafted films. The prepared films were further characterized with stereo micrograph and XRD. Finally, the produced film can be used as biodegradable packaging materials for shopping and garbage bags that are very popular and environment friendly.

Preparation and Characterization of the Mechanical Properties of the Photocured Chitosan/Starch Blend Film

The chitosan/starch blend films of 2:1 ratio were prepared by solution casting. Tensile strength (TS) and elongation at break (%Eb) of chitosan/starch blend film were found to be 9.33 MPa and 3.6%, respectively. The blend films (2% Chitosan) were soaked in six different formulations of methylmethacrylate (MMA) monomer and aliphatic urethane diacrylate oligomer (M-1200) at different time intervals (1–5 min) and irradiated under UV radiation at different intensities (5–35 pass). Formulations containing 43% MMA and 15% oligomer in methanol solution showed 209% increase in TS at 25th UV pass for 4 min soaking time. SEM and FTIR were used to investigate the molecular interaction and morphology of the blend film, respectively.

Thermal, Mechanical and Morphological Characterization of Jute/Gelatin Composites

Jute fabrics/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 20–60 wt%. Composites were subjected to mechanical, thermal, water uptake and scanning electron microscopic (SEM) analysis. Composite contained 50 wt% jute showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the 50% jute content composites were found to be 85 MPa, 1.25 GPa, 140 MPa and 9 GPa and 9.5 kJ/m2, respectively. Water uptake properties at room temperature were evaluated and found that the composites had lower water uptake compared to virgin matrix.

Study on the Effect of Urea on the Mechanical and Morphological Properties of Jute/Gelatin Composites

Composites of jute fabric and gelatin were prepared by solution casting or solution-impregnation technique. Jute content in the composite was optimized on the basis of their mechanical properties. Composite containing 50% jute showed best mechanical properties in terms of tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS). Incorporation of urea into the composite showed better improvement in the mechanical properties than the untreated composites. Scanning electron micrographs of the urea treated composites showed better adhesion between gelatin matrix and jute fabrics.

Development of Urea Crosslinked Thin Film for Biomedical Application

Bioadhesive thin film was prepared from gelatin using urea as plasticizer as well as crosslinker. Viscosity of the solution showed a decreasing trend with increasing heating time. Nevertheless, viscosity and pH increased with increasing urea content and heating time to a certain level. Mechanical properties and fluid drainage capability of the films of blend solutions were also evaluated. Tensile strength showed a mixed behavior with urea content and heating but flexibility increased with urea content. Besides, crosslinked film showed no cytotoxic effect rather fluid absorption capability was improved. All of these results suggest its potentiality for effective wound dressing material.

Preparation and Characterization of an Alginate/Clay Nanocomposite for Optoelectronic Application

Sodium Alginate/bentonite clay composites of different compositions were prepared by solution casting method. The electrical properties (Conductivity, Dielectric constant) of the composites were investigated by standard methods with Impedance Analyzer. The electrical properties were found to improve with the incorporation of bentonite clay. The thermal, physical and mechanical properties of sodium alginate/bentonite clay composite were investigated by Thermo-Mechanical Analyzer (TMA), X-ray Deffraction (XRD), and Universal Testing Machine respectively. . Tensile Strength (TS) and Elongation at break (Eb) of 2% clay containing composite film were found to be 7.6 MPa and 55% respectively. The XRD demonstrates the enhancing crystallinity of sodium alginate/bentonite clay composite with the increasing clay content. TMA results showed a higher thermal stability in the composite. Water absorption properties of the sodium alginate/clay composite were studied and found to decrease with the increase of clay content. . The inter action between sodium alginate and bentonite clay were studied by Fourier transform infrared spectroscopy (FT-IR). All of the results indicate that the developed composite is promising for use in a wide variety of optoelectronic applications.

Extraction and characterization of crystalline cellulose from jute fiber and application as reinforcement in biocomposite: Effect of gamma radiation

In this study, crystalline cellulose was prepared through hydrolysis of jute fiber and was used as reinforcement of gelatin-based biocomposite film. The effects of crystalline celluloses loading on the morphology, mechanical properties and water sensitivity of the biocomposite were investigated by means of Scanning electron microscopy, tensile strength testing and water absorption testing. The developed biocomposite film showed homogeneous dispersion of crystalline celluloses within the gelatin matrix and strong interfacial adherence between matrix and reinforcement. A significant increase in tensile strength and E Modulus was also found (tensile strength was 25.4 MPa for pure gelatin and 48.2 MPa for 2% crystalline celluloses/gelatin film at 45% relative humidity), which was further induced by gamma radiation. The resulting biocomposite film also showed a higher water resistance and excellent biocompatibility. Therefore, crystalline celluloses played an important role in improving the mechanical properties as well as water resistance of the biocomposite film.

Development of hydrocolloid Bi-layer dressing with bio-adhesive and non-adhesive properties

Bio-active bi-layer thin film having both bio-adhesive and non-adhesive end composed of polyvinyl alcohol (PVA) and gelatin/chitosan/polyethylene glycol (PEG) blend was developed for biomedical applications especially as an alternative of advanced tissue scaffold. The developed composite film was subjected to mechanical, thermal and physico-chemical characterization such as tensile strength (TS) and elongation at break (Eb), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), fluid drainage capacity and biocompatibility. Suitable packaging was also selected and stability study and aging test of the composite film were performed after packing. The incorporation of chitosan and PEG into gelatin showed improved mechanical properties of both TS and Eb, which suggested the occurrence of interaction among gelatin, chitosan and PEG molecules in the composite film. The presence of crosslinking as an interaction of above three polymers was also confirmed by FTIR study. Results from the DSC study suggested increased thermal stability after crosslinking. On the other hand, water uptake studies suggested excellent fluid drainage capability and hydro-stability of the composite film. The proposed dressing also showed excellent biocompatibility. Based on the studies related to the performance with confirmed identity, we concluded that our developed bi-layer film is very potential as an ideal wound dressing material.