Aspectos morfológicos da utilização intraperitoneal de prótese de dupla face na inguinoplastia em cães

Recent advances and perspectives on natural latex serum and its fractions for biomedical applications

Advances and the discovery of new biomaterials have opened new frontiers in regenerative medicine. These biomaterials play a key role in current medicine by improving the life quality or even saving the lives of millions of people. Since the 2000s, Natural Rubber Latex (NRL) has been employed as wound dressings, mechanical barrier for Guided Bone Regeneration (GBR), matrix for drug delivery, and grafting. NRL is a natural polymer that can stimulate cell proliferation, neoangiogenesis, and extracellular matrix (ECM) formation. Furthermore, it is well established that proteins and other biologically active molecules present in the Natural Latex Serum (NLS) are responsible for the biological properties of NRL. NLS can be obtained from NRL by three main methods, namely (i) Centrifugation (fractionation of NRL in distinct fractions), (ii) Coagulation and sedimentation (coagulating NRL to separate the NLS from rubber particles), and (iii) Alternative extraction process (elution from NRL membrane). In this review, the chemical composition, physicochemical properties, toxicity, and other biological information such as osteogenesis, vasculogenesis, adhesion, proliferation, antimicrobial behavior, and antitumoral activity of NLS, as well as some of its medical instruments and devices are discussed. The progress in NLS applications in the biomedical field, more specifically in cell cultures, alternative animals, regular animals, and clinical trials are also discussed. An overview of the challenges and future directions of the applications of NLS and its derivatives in tissue engineering for hard and soft tissue regeneration is also given.

Morphological and morphometric analyses of crushed sciatic nerves after application of a purified protein from natural latex and hyaluronic acid hydrogel

Hyaluronic acid hydrogels (HAHs) have been used as a carrier of substances and factors in the repair of nervous tissue. Natural latex protein (Hevea brasiliensis, F1) has shown positive effects in treating various types of tissues, including peripheral nerves. This study evaluated the F1 associated with a HAH in a controlled crush injury (axonotmesis) of the sciatic nerve in Wistar rats. The samples were photomicrographed for morphometric and quantitative analyzes using ImageJ 1.47k software (NIH, Bethesda, MD). Morphological, quantitative (myelin area/nerve area ratio and capillary density) and morphometric (minimum nerve fiber diameter, G-Ratio) data revealed an improvement in the recovery of the sciatic nerve with the application of HAH and the combination of HAH and F1 after 4 and 8 weeks of nerve injury. The most efficacious results were observed with the combination of both substances, F1 and HAH, revealing the regenerative capacity of this new biomaterial, which was hardly tested on nerve tissue.

Application of a low-level laser therapy and the purified protein from natural latex (Hevea brasiliensis) in the controlled crush injury of the sciatic nerve of rats: a morphological, quantitative, and ultrastructural study

This study analyzed the effects of a low-level laser therapy (LLLT, 15 J/cm², 780 nm wavelength) and the natural latex protein (P1, 0.1%) in sciatic nerve after crush injury (15 Kgf, axonotmesis) in rats. Sixty rats (male, 250 g) were allocated into the 6 groups (n = 10): CG—control group; EG—nerve exposed; IG—injured nerve without treatment; LG—crushed nerve treated with LLLT; PG—injured nerve treated with P1; and LPG—injured nerve treated with LLLT and P1. After 4 or 8 weeks, the nerve samples were processed for morphological, histological quantification and ultrastructural analysis. After 4 weeks, the myelin density and morphological characteristics improved in groups LG, PG, and LPG compared to IG. After 8 weeks, PG, and LPG were similar to CG and the capillary density was higher in the LG, PG, and LPG. In the ultrastructural analysis the PG and LPG had characteristics that were similar to the CG. The application of LLLT and/or P1 improved the recovery from the nerve crush injury, and in the long term, the P1 protein was the better treatment used, since only the application of LLLT has not reached the same results, and these treatments applied together did not potentiate the recovery.

Morphologic evaluation of the use of a latex prosthesis in videolaparoscopic inguinoplasty: an experimental study in dogs

PURPOSE

To evaluate the morphological aspects of the behavior of 4 types of latex biomembranes implanted in preperitoneal videolaparoscopic inguinoplasty.

METHODS

Sixteen inguinoplasties were performed in 12 dogs: group 1 received an impermeable latex biomembrane in the right inguinal region and a prolene prosthesis, as control, in the contralateral inguinal region; groups 2, 3 and 4 received latex biomembranes respectively containing impermeable polyamide, 1-mm thick porous polyamide and 0.5-mm thick porous polyamide. Macro- and microscopic evaluations of the inguinal region and of the removed implants were made on the 7th, 14th, 21st and 28th days in group 1 and on the 28th postoperative day in the other groups.

RESULTS

We observed absence of hematoma, seroma and infection; presence of tortuosities; induction of vascular neoformation, inflammatory reaction and collagen deposition, and full encystment of the latex biomembranes, except that with fine porous polyamide, which was partially incorporated, with the formation of microcysts. No latex biomembrane induced fibrosis as observed in the prolene control group.

CONCLUSIONS

The biomembranes maintain induction of the healing process without fibrosis, are fully encysted and, except for the one with fine porous polyamide, are not incorporated into adjacent tissues. The latex biomembrane, with or without polyamide, is not recommended as a separate material for preperitoneal inguinoplasty.