Oxytocin Sustained Release Using Natural Rubber Latex Membranes

Abstract

The demand for biomaterials with properties that provide sustained release of substances with pharmacological interest is constant. One candidate for applications in this area is the Natural Rubber Latex (NRL) extracted from the rubber tree Hevea brasiliensis. Recent studies indicate the NRL as a matrix for sustained release, showing promising results for biomedical applications such as: can stimulate natural angiogenesis and is capable of adhering cells on its surface, promoting the replacement and regeneration of tissue. So, the NRL is an excellent candidate to propitiate the sustained release of peptides of pharmacological interest such as oxytocin, a hormonal peptide which has the function to promote uterine muscle contractions and reduce bleeding during childbirth, and stimulate the release of breast milk. Results demonstrated that 90 lg mL-1 (45 %) of the incorporated peptide in Natural Rubber Latex Biomedical (NRLb) functionalized membranes was released at 10 h in phosphate-buffered saline (PBS) solution. Swelling kinetics assay showed that the NRLb membranes are able to absorb over a period of 16 h up to 1.08 grams of water per grams of membrane. Scanning electron microscopy showed that the peptide was adsorbed on the surface and within NRLb membrane. Fourier transform infrared and Derivative Thermo-gravimetric analysis indicated that oxytocin did not interacted chemically with the membrane. Furthermore, hemolysis of erythrocytes, quantified spectrophotometrically using materials (Oxytocin, NRLb, and NRLb ? Oxytocin) showed no hemolytic effects up to 100 lg mL-1 (compounds and mixtures), indicating no detectable disturbance of the red blood cell membranes. Based on these results it was possible to conclude that the NRLb has shown effectiveness as a model in the release of peptides with pharmacological interest.

Natural latex‐glycerol dressing to reduce nipple pain and healing the skin in breastfeeding women

“…Under these conditions, NRL and NRL‐glycerol membranes showed no hemolytic effects indicating no detectable disturbance of the red blood cell membranes. These results are similar to those obtained by Borges et al 8‐33 and Barros et al . The test was realized according to the international standard ISO 10993‐4:2002, showing that the membrane NRL‐glycerol has no cytolytic activity.…”

“…The FTIR spectrum from NRL membrane shows the characteristics transmissions for poly( cis ‐1,4‐isoprene): 2960 and 1374 cm −1 CH 3 stretching; 2914, 2849, and 1446 cm −1 CH 2 stretching; 1663 cm −1 C‐C stretching; and 839 cm −1 CH out off‐plan. This last transmission is the most important to identify NRL since this band is characteristic from R 2 C=CHR ( cis ‐1,4) function . Figure shows the FTIR spectra from pure glycerol, NRL, and NRL‐glycerol.…”

“…The cream fraction after centrifugation was redispersed to make the desired 60% of dry rubber content latex and then washed twice by centrifugation to reduce the protein content on the solution. The NRL has 0.22% of proteins in its composition, 27% of these proteins are removed during the deproteinization process for obtaining the NRLb with 0.16% of proteins . The glycerol (C 3 H 8 O 3 ) was purchased from Sigma‐Aldrich (St. Louis.…”

“…The NRL has 0.22% of proteins in its composition, 27% of these proteins are removed during the deproteinization process for obtaining the NRLb with 0.16% of proteins. 15 The glycerol (C 3 H 8 O 3 ) was purchased from Sigma-Aldrich (St. Louis. MO, USA).…”

“…[11][12][13] In addition to presenting tissue repair properties, the natural rubber latex can also act as a solid support for sustained release of compounds of pharmacological interest. [14][15][16][17][18][19][20][21] In the present work, glycerol was incorporated into natural rubber latex with the objective of acting as a moisturizing compound to maintain hydration in the nipple region. 22…”