Biology subjects

Barraviera, B.

Publications and source records attributed to Barraviera, B..

3 recordsLinked to original sources

bioRxiv2020

SEEKING CANDIDATE MOLECULES AS PROGNOSTIC HEALING MARKERS IN CHRONIC VENOUS ULCERS

Seeking and identifying biomarker molecules in inflammatory exudate of chronic venous ulcers (CVUs) can aid health professionals in the healing prognosis. The therapeutic failure or cure is related to the quantitative expression of determinate proteins. This work aimed to identify the proteins expressed in inflammatory exudates from CVUs and correlate them with reduction or increase in the wound size. For 90 days, 28 participants that received standard treatment for 37 CVUs were monitored. The inflammatory exudates were collected before treatment initiation (T=0) and analyzed via the Label-free Shotgun. After 90 days the wound area was reduced in 25 (67.6%) of them. Mass spectrometry analysis of all the inflammatory exudates showed four proteins differentially expressed and related to favorable or unfavorable evolution of the healing process. Complement C3 and ceruloplasmin were identified in all the lesions analyzed and were expressed differentially in lesions that presented diminished area in the studied period. Apoliprotein A1 and neutrophil defensin-1 presented differential expression in ulcers that either did not diminish or augmented their wound area through 90 days. These results suggest that Complement C3, Ceruloplasmin, Apoliprotein A1 and Neutrophil-defensin-1 proteins are potential candidate molecules for prognostic healing markers in chronic venous ulcers.

biochemistry↗

bioRxiv2019

Improvement of bone regeneration using fibrin biopolymer combined with differentiated stem cells

1.Bone tissue repair remains a challenge on tissue engineering. New approaches are highly expected to regenerate fractures, bone infections, cancers and congenital skeletal abnormalities. Lately, osteoconductive biomaterials have been used with osteoprogenitor cellsas bone substitutes to accelerate bone formation. Fibrin scaffold serves as a provisional platform promoting cell migration and proliferation, angiogenesis, connective tissue formation and growth factors stimulation. When combined with mesenchymal stem cells (MSCs) maintain cell viability that exerts an immunomodulatory effect by modifying inflammatory environment through expression of pro and anti-inflammatory cytokines. We evaluated a unique heterologous fibrin biopolymer as scaffold to MSCs on bone regeneration of rat femurs. A critical-size bone defect was made in the femur and treated with fibrin biopolymer(FBP); FBP + MSC; and FBP + MSC differentiated in bone lineage (MSC-D). Bone repair was analyzed 03, 21 and 42 days later by radiographic, histological and scanning electron microscopy (SEM) imaging. The FBP+MSC-D association was the most effective treatment, since newly formed bone was more abundant and early matured in just 21 days. Our results demonstrate that FBP isolated was able to promote bone repair although cells play a crucial role on the type and quantity of bone tissue formed. We have not observed surgical site infection, inflammatory response, fractures or loss of function related with FBP. Thus, this approach can be safely expanded for clinical trials as an effort to overcome current method limitations and improve overall bone regeneration process.

bioengineering↗

bioRxiv2018

A method for faster purification of serine proteinases from Bothrops alternatus and Bothrops moojeni snake venoms

Snake venoms are important sources of substances with a variety of pharmacological activities. Among the different proteins present in these venoms, snake venom serine proteinases (SVSPs) have important effects on the hemostatic system that influence the hemodynamic properties of blood. Bothrops genus snakes presented their venom richly composed of SVSPs thrombin-like, and the isolation of these enzymes is of great interest. In 1994, the Center for the Study of Venoms and Venomous Animals (CEVAP) - UNESP standardized the fibrin sealant derived from snake venom, replacing the bovine thrombin by gyroxin thrombin-like enzyme from Crotalus durissus terrificus (Rattlesnake) and human plasma fibrinogen by buffaloes cryoprecipitate. Despite chromatographic techniques for the purification of gyroxin be well grounded in the literature, that income is considered low. Thus, in addition to gyroxin, other thrombin-like enzymes could be employed in the composition of the new fibrin sealant after being standardized to the purifying and chromatographic performance and widely evaluated for biological activities. Therefore, it is extremely important that in our lab is deployed, standardized and validated a method for the chromatographic purification of other thrombin-like enzymes such as found in Bothrops snake venoms. Thus a two-step chromatographic procedure was developed to routinely purify serine proteinases from Bothrops alternatus and B. moojeni snakes venoms to provide new enzymes for improving the CEVAPs heterologous fibrin sealant.

biochemistry↗