Catalyst-Free Click Chemistry for Engineering Chondroitin Sulfate-Multiarmed PEG Hydrogels for Skin Tissue Engineering.

The quest for an ideal biomaterial perfectly matching the microenvironment of the surrounding tissues and cells is an endless challenge within biomedical research, in addition to integrating this with a facile and sustainable technology for its preparation. Engineering hydrogels through click chemistry would promote the sustainable invention of tailor-made hydrogels. Herein, we disclose a versatile and facile catalyst-free click chemistry for the generation of an innovative hydrogel by combining chondroitin sulfate (CS) and polyethylene glycol (PEG). Various multi-armed PEG-Norbornene (A-PEG-N) with different molecular sizes were investigated to generate crosslinked copolymers with tunable rheological and mechanical properties. The crosslinked and mechanically stable porous hydrogels could be generated by simply mixing the two clickable Tetrazine-CS (TCS) and A-PEG-N components, generating a self-standing hydrogel within minutes. The leading candidate (TCS-8A-PEG-N (40 kD)), based on the mechanical and biocompatibility results, was further employed as a scaffold to improve wound closure and blood flow in vivo. The hydrogel demonstrated not only enhanced blood perfusion and an increased number of blood vessels, but also desirable fibrous matrix orientation and normal collagen deposition. Taken together, these results demonstrate the potential of the hydrogel to improve wound repair and hold promise for in situ skin tissue engineering applications.

Time is life: EpAssistant - a new tool for the automatic identification of anti-HLA antibody epitope specificity in transplant programs.

BACKGROUND AND OBJECTIVES: This work aims to present the expert system EpAssistant, a platform algorithm designed to accurately and automatically identify the EPLETS specificities of anti-HLA (Human Leukocyte Antigen) antibodies in the sera of transplantation candidates. MATERIALS AND METHODS: RESULTS: As preliminary results, we present the development and establishment of the EpAssistant platform. EpAssistant analyses can be performed for Class I (-A, B and C) and Class II (-DR, -DQ and -DP) HLA molecules. CONCLUSIONS: EpAssistant automates the EPLETS reactivity analysis process and drastically reduces the time required to produce final results, enabling large-scale data analyses in a simple, inexpensive and rapid manner and facilitating the allocation of donated organs via the EPLETS Virtual Crossmatch (EVxM) system.

Web-based ecosystem software for virtual crossmatching in transplant programs.

BACKGROUND: The compatibilities between donors and recipients are extremely important for evaluating the immunological risks of transplants. One challenge faced by data analysis tools is the transformation of complex data into simple, intuitive, and important information that can be used to resolve contemporary problems. To address this challenge, we developed the EpViX software to perform epitope reactivity analyses and automated epitope virtual crossmatching. EpViX is a facilitator of medical decision-making regarding the identification of the best donor for a high-immunologic risk recipient. The objective of this work is to describe the computational architecture of the EpViX ecosystem (http://www.epvix.com.br). MATERIALS AND METHODS: EpViX is a freeware on the web that was developed in the Ruby language. EpViX can be accessed from different platforms, e.g., PCs, tablets, and smartphones. It consists of an ecosystem of tools that are capable of integrating all of the stakeholders who are involved in a transplant process with a deceased donor. RESULTS: We successfully developed a program that allows people to work collaboratively and effectively during the donation process by accurately predicting negative crossmatches, saving time and other resources. CONCLUSIONS: EpViX represents a significant breakthrough for the organ transplant process and may meet the current needs of transplant programs because it increases the chances of the allocation of low-immunologic risk donors to highly sensitized recipients and assures greater equity among the recipients on a waiting list. EpViX was duly verified and tested in terms of data security. Moreover, usability tests demonstrated that EpViX is an intuitive and easy-to-use tool.

First report on the antibody verification of HLA-DR, HLA-DQ and HLA-DP epitopes recorded in the HLA Epitope Registry.

The International Registry of Antibody-Defined HLA Epitopes (http://www.epregistry.com.br) has been recently established as a tool to understand humoral responses to HLA mismatches. These epitopes can be structurally defined as eplets by three-dimensional molecular modeling and amino acid sequence differences between HLA antigens. A major goal is to identify HLA eplets that have been verified experimentally with informative antibodies. This report addresses class II epitopes encoded by genes in the HLA-D region. Our analysis included reviews of many publications about epitope specificity of class II reactive human and murine monoclonal antibodies and informative alloantibodies from HLA sensitized patients as well as our own antibody testing results. As of July 1, 2014, 24 HLA-DRB1/3/4/5, 15 DQB, 3 DQA and 8 DPB antibody-verified epitopes have been identified and recorded. The Registry is still a work-in-progress and will become a useful resource for HLA professionals interested in histocompatibility testing at the epitope level and investigating antibody responses to HLA mismatches in transplant patients.

Lysosome-associated protein 1 (LAMP-1) and lysosome-associated protein 2 (LAMP-2) in a larger family carrier of Fabry disease.

This study investigated the potential relationship between the expression levels of lysosome-associated membrane proteins (LAMP) 1 and 2 and responses to enzyme replacement therapy (ERT) in the members of a single family with Fabry disease (FD). LAMP levels were assessed by flow cytometry in leukocytes from 17 FD patients who received an eight-month course of ERT course and 101 healthy individuals. We found that phagocytic cells from the FD patients had higher expression levels of both LAMP-1 and LAMP-2, relative to the levels in phagocytes from the healthy controls (p=0.001). Furthermore, the LAMP-1 and LAMP-2 levels in phagocytes from the FD carriers continuously decreased with ERT administration to reach levels similar to those in healthy controls. We suggest that LAMP-1 and LAMP-2 could be used as additional markers with which to assess ERT effectiveness in FD.