The search for new therapies and
drugs that act as topical agents to relieve pain and control the inflammatory
processes in burns always attracted interest in clinical trials. As
an alternative to synthetic drugs, natural extracts are useful in
the development of new strategies and formulations for improving the
quality of life. The aim of this study was to develop a wound dressing
using poly(l-co-d,l-lactic
acid-co-trimethylene carbonate) (PLDLA-TMC) containing Schinus terebinthifolius Raddi (S.T.R.). S.T.R. is
a native Brazilian plant known for its strong anti-inflammatory responses.
The membrane of PLDLA-TMC + S. terebinthifolius Raddi was prepared at different concentrations of S.T.R. (5, 10,
15, and 50%). The Fourier transform infrared results showed no change
in the PLDLA-TMC spectrum after S.T.R. addition, whereas the swelling
test showed changes only in PLDLA-TMC + S.T.R. at 50%. The wettability
measurements showed a mass loss due to the decrease in the contact
angle in all samples after the S.T.R. addition in the polymer, whereas
the S.T.R. release test showed a linear delivery pattern. The scanning
electron microscopy analysis showed that S.T.R. was homogeneously
distributed at only 5 and 10%. Tensile tests demonstrated an increase
in Young’s modulus and a reduction in the elongation till rupture
of PLDLA-TMC after the addition of S.T.R. The biocompatibility in
vitro evaluation with rat fibroblast cells seeded in the membranes
of PLDLA-TMC + S.T.R. showed that although S.T.R. interfered in cell
morphology, all concentrations tested showed that cells were able
to adhere and proliferate during 7 days. Thus, S.T.R. at 50% was chosen
to be tested for in vivo trials. The histological and immunohistochemistry
results revealed an accelerated skin healing at 7 days after controlled
secondary burns were introduced in the dorsal skin, with a striking
total recovery of the epidermis and high rates of molecular activation
of cell proliferation. Due to the known biocompatibility properties
of PLDLA-TMC and its stable release of S.T.R., we strongly recommend
S.T.R.-containing PLDLA-TMC as a curative device to favor skin healing.