Improvement in mechanical properties and biodegradability of PLA using poly(ethylene glycol) and triacetin for antibacterial wound dressing applications

Abstract

Wound is among the most common injuries. A suitable wound dressing has a significant effect on the healing process. In this study, a porous wound dressing was prepared using poly (lactic acid) (PLA) and two plasticizers, polyethylene glycol (PEG) and triacetin (TA), through solvent casting method. For antibacterial activities, metronidazole was incorporated in the structure. The morphology was investigated by scanning electron microscopy (SEM). In addition, the effect of plasticizers ratio on porosity growth was evaluated. It was also observed that each had a unique effect on the structure's porosity. The mechanical properties confirmed the effect of both plasticizers on increasing polymer softness and flexibility, and the most similar formulations to human skin in terms of mechanical properties were introduced. According to the results, TA had stronger effect on mechanical properties. The differential scanning calorimetry (DSC) showed the effect of increasing plasticizer concentration on crystalline structure and T m reduction of PLA. The water contact angle measurement showed that both plasticizers enhanced hydrophilic characteristics of PLA, and this effect was weaker in PEG-containing formulations. The in vitro degradation study showed biodegradability, as a desirable property in wound dressing. Results suggested that higher degradation can be obtained by both plasticizers at the same time. The results also showed that PEG was more effective in enhancing water absorbency. In vitro drug release study indicated an explosive release and the highest amount was 85% over 186 h. The antibacterial activity test confirmed the effectiveness of the drug in preventing bacterial growth in the drug-containing formulations, while it showed the antibacterial property of TA. MTT assay was performed and the cellular toxicity of the formulations was checked and those that revealed the least toxicity were introduced.

In Vitro Degradation of Specimens Produced from PLA/PHB by Additive Manufacturing in Simulated Conditions

“…Similar results were obtained by Darabian et al; in their study, they examined two different plasticisers. As to the absorption, the results clearly showed that a similar phenomenon has been observed in the samples containing polylactic acid (PLA) and TAC, in particular that the water absorbency increases with an increasing TAC [ 7 ].…”

The effect of alginate scaffolds on bone healing in defects formed with drilling model in rat femur diaphysis

“…It was observed that modification of alginate with TA and TBC increased the degradation rate of the scaffolds ( P < .05). Darabian et al expressed that TA decreased PLA scaffold degradation 28 . Kurowiak et al demonstrated that the mass of alginate hydrogels cross‐linked with Ca‐Ba was about 18% 29 .…”

“…Zhu et al also used triacetin for starch ester films, and they observed that triacetin decreased the thermal stability of starch film 36 . Darabian et al reported that mixing TA decreased melting enthalpy of poly lactic acid scaffold 28 …”

Study of Thermal, Phase Morphological and Mechanical Properties of Poly(L-lactide)-b-Poly(ethylene glycol)-b-Poly(L-lactide)/Poly(ethylene glycol) Blend Bioplastics

“…However, many pores were detected on the PLLA film matrices when the PEG was blended. These pore structures occurred from the infiltration of blended PEG and solvent into bulk PLLA during solvent evaporation [35,36]. Coalescence of these pores was detected for the 80/20 PLLA/PEG blend film [Fig.…”