Polymeric films containing pomegranate peel extract based on PVA/starch/PAA blends for use as wound dressing: In vitro analysis and physicochemical evaluation.

Chronic wounds constitute a serious public health problem, and developing pharmaceutical dosage forms to ensure patient comfort and safety, as well as optimizing treatment effectiveness, are of great interest in the pharmaceutical, medical and biomaterial fields. In this work, the preparation of films based on blends of poly(vinyl alcohol), starch and poly(acrylic acid), polymers widely used as pharmaceutical excipients, and pomegranate peel extract (PPE), a bioactive compound with antimicrobial and healing activities relevant to the use as a bioactive wound dressing, was proposed. Initially, the minimum inhibitory concentration (MIC) of the PPE was investigated by an in vitro method. Then, the best concentration of the PPE to be used to prepare the films was researched using an antimicrobial susceptibility test with the disc diffusion method. The microbiological assay was performed in films prepared by the solvent casting method in the presence of two concentrations of PPE: 1.25% w/v and 2.5% w/v. Films containing the lower PPE concentration showed antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermidis, with a difference that was not considered statistically significant when compared to the higher concentration of the extract. Therefore, the films prepared with the lower proportion of PPE (1.25% w/v) were considered for the other studies. The miscibility and stability of the extract in the films were investigated by thermal analysis. Parameters that determine the barrier properties of the films were also investigated by complementary techniques. Finally, in vitro biological tests were performed for safety evaluation and activity research. Analysis of the results showed that the incorporation of the higher proportion of starch in the blend (15% v/v) (PVA:S:PAA:PPE4) yielded smooth, transparent, and domain-free films without phase separation. Additionally, the PVA:S:PAA:PPE4 film presented barrier properties suitable for use as a cover. These films, when subjected to the in vitro hemolytic activity assay, were nonhemolytic and biocompatible. No toxicity from the extract was observed at the concentrations studied. The results of the wound healing in vitro test showed that films containing 1.25% PPE are efficient in reducing the scratch open area, provoking almost total closure of the scratches within 48 h without cytotoxicity.

Biodegradable core-shell electrospun nanofibers containing bevacizumab to treat age-related macular degeneration.

Age-related macular degeneration (AMD) is a degenerative ocular disease that affects the central retina. It is considered the main cause of blindness and loss of vision worldwide. Angiogenic factors are associated with AMD, which has led to the use of antiangiogenic drugs, such as bevacizumab, to treat the disease using frequent intravitreal injections. In the present study, biodegradable core shell nanofibers containing bevacizumab were prepared by the coaxial electrospinning technique. It is thought that the shell could control the release of the drug, while the core would protect and store the drug. Poly(caprolactone) (PCL) and gelatin were used to form the shell of the nanofibers, while poly(vinyl alcohol) (PVA) and bevacizumab comprised the core. The nanofibers were characterized using microscopy techniques, thermal analysis, and FTIR. The results showed that core-shell nanofibers were produced as designed. Bevacizumab activity was evaluated using a chicken embryo chorioallantoic membrane (CAM) assay. An enzyme-linked immunosorbent assay was used to quantify the amount of the drug released from the different nanofibers in vitro. The toxicity of the nanofibers was evaluated in human retinal pigment epithelial (ARPE) cells. The CAM results demonstrated that bevacizumab maintained its antiangiogenic activity when incorporated into the nanofibers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests revealed that the nanofibers showed no cellular toxicity, even in the presence of bevacizumab. The core-shell structure of the nanofibers reduced the release rate of bevacizumab compared with PVA nanofibers. The bevacizumab-loaded biodegradable nanofibers presented interesting properties that would potentially constitute an alternative therapy to intravitreal injections to treat AMD.