Preparation of Polypropylene/silver nanoparticles Nanocomposite films and Evaluation of its Barrier and Antimicrobial Properties for Packaging Applications

Polymeric films which can be used in packaging industries were prepared by blown film method with polypropylene chips and silver nanoparticles. The nanocomposite films were characterized concerning its potential use. Oxygen Transmission rate (OTR) measurements was done in order to ascertain permeability of oxygen through the polymeric films. It was found that the permeability of oxygen through nanocomposite film is higher than that of virgin polypropylene film due to incompatibility between polypropylene matrix and silver nanoparticles. The water vapour transmission rate (WVTR) test of the polymeric nanocomposite films was calculated in order to know the information about mass transfer mechanisms and solute-polymer interactions in the food packaging film. It has been found that, there is a significant decreased water vapour transmission rate through nanocomposite films compared to that of virgin polypropylene film. With increasing the concentration of silver nanoparticles, this effect was reduced. The explanation for this could be that with higher concentration of silver nanoparticles agglomeration in the polymer film could the possibility which create narrow pathway for water molecules to travel. The effect of various silver nanoparticles content in the polymer nanocomposites with respect to its antimicrobial efficacy against the Gram positive bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus were studied. However, Escherichia coli was most effectively retarded by silver nanoparticles than Staphylococcus aureus, which is related to the difference in the cell wall of the gram positive and gram negative bacteria.

Swelling Behaviour and Water Vapour Transmission Rates of Gellan Gum/Collagen Film Containing Gatifloxacin as Dressing Materials

In an effort to produce ideal wound dressing, gellan gum/collagen hydrogel films containing different concentrations of gatifloxacin were prepared via evaporative casting method. The films were examined in terms of physical appearances, water uptake and water vapour transmission rate (WVTR). All the films showed good physical appearances. Swelling percentages of the films were decreased, whereas WVTR values were increased as the addition of gatifloxacin was increased. Swelling percentage of gellan gum/collagen film with the lowest percentage of gatifloxacin (GG/C-GAT01) has the highest swelling ratio (2057%). Meanwhile, the WVTR value of GG/C-GAT1 has the highest WVTR value among all films which is 1245 g m-2 day-1. The formulation of GG/C films with the addition of gatifloxacin with good water absorbance and acceptable WVTRs value offered promising materials to be applied as wound dressing materials.

Functional Characteristics Improvement of Edible Film through the Addition of Gambier and Bay Leaf Extract

Background: Composing functional edible film focused on local materials has been explored in this study. However, producing an edible film with strong capability as an antioxidant and antimicrobe has not been successful. The incorporation of one or more functional compounds, such as gambier extract and bay leaf extract into canna starch, should offer the solution. Objective: These compounds should work in synergy in order to improve the functional characteristics of edible film. Furthermore, the film should have mechanical characteristics which fulfille Japan Industrial Standard (JIS) (1975), i.e., it should belong to a strong category. Methods: This research studied the effects of gambier extract and bay leaf extract addition on edible film characteristics. A completely randomized design was used, and two factors were investigated, namely gambier extract (1.0, 2.0, and 3.0 percent, w/v) and bay leaf extract (0.0, 3.0, and 6.0 percent, w/v). Results: The parameters that were observed included mechanical (thickness, elongation percentage, water vapour transmission rate) as well as functional characteristics (antioxidant and antibacterial activity). The results showed that thickness, elongation percentage and water vapour transmission rate of the functional edible film were 0.18 - 0.27 mm, 7.33 - 9.00% and 30.43 - 46.07g.m-2.d-1, respectively, whereas antioxidant and antibacterial activity (value of inhibition diameter) were 23.24 - 40.58 mg.mL-1 and 1.33 - 1.83 mm, respectively. Conclusion: Edible film produced in this research had an antioxidant activity of strong category with a thickness that fulfilled JIS 1975 standard.

Effect of different concentrations of corn starch and whey protein on the characteristics of biodegradable cup

An attempt was made to prepare a composite biodegradable cup using corn starch, whey protein, carboxymethyl cellulose and glycerol. For biodegradable cup formation, corn starch (5-7%), WPC-35 (1.5-3%), CMC (0.5-2%) and glycerol (2-4%) range was selected. To decide upon temperature at which the cup forming solution attains final viscosity, samples were tested under rapid visco analyser to conclude that layering was enabled at 50oC. Based on observations three best biodegradable cups combinations were selected Sample A (corn starch 7%, WPC-35 3%, Cellulose 2%, glycerol 2.5%); Sample B (corn starch 7%, WPC-35 2%, Cellulose 2%, glycerol 2.5%); Sample C (corn starch 7%, WPC-35 3%, Cellulose 2%, glycerol 4.0%). Properties like thickness, solubility, water vapour transmission rate, viscosity, moisture, lightness were studied for three samples to select the final cup. Based on observation, Sample C's final composition was selected as corn starch 7%, WPC-35 3%, cellulose 2%, glycerol 4.0%. The value for thickness, solubility, WVTR, moisture and lightness was observed as 0.5±0.025mm, 48.50±0.66%, 1.14±0.086g/m2/hr, 7.74±0.16%, 41.96±1.86 respectively. The lower diameter of the cup was observed as 5.5cm, upper diameter 7.5cm and height of cup was observed as 4.0 cm with the capacity of the final cup as 55.5ml/47.1gm.

Synthesis and evaluation of an alginate-methacrylate xerogel for insulin delivery towards wound healing applications

Background: Alginate is one of the most widely used biopolymer for wound healing. But poor mechanical strength and degradability limits its application especially as a drug-delivery matrix. The aim of this study was to develop stable alginate based scaffold for insulin delivery toward wound care. Materials & methods: The xerogel alginate-g-poly (methacrylic acid; AGM2S) was characterized by various analytical techniques. Results: AGM2S xerogel showed improved physical stability, low degradation, good swelling and water vapour transmission rate (WVTR). About 70% of insulin was released from loaded xerogel over a period of 48 h and favorably modulated the healing response in in vitro scratch wound assay. Conclusion: Grafting improved the strength and stability of alginate xerogel and the results suggest the application of insulin loaded AGM2S xerogels as a potential wound healing material.