Highly absorbent bio-sponge based on carboxymethyl chitosan/poly-γ-glutamic acid/platelet-rich plasma for hemostasis and wound healing.

Stopping bleeding at an early stage and promoting wound healing are of great significance for efficient wound management. In this study, a carboxymethyl chitosan (CMCS)/poly-γ-glutamic acid (γ-PGA)/platelet-rich plasma (PRP) hydrogel (CP-PRP hydrogel) was firstly prepared by crosslinking of CMCS with γ-PGA and the enzymatic coagulation of PRP. Then, the CP-PRP hydrogel was freeze-dried and transformed into a sponge (CP-PRP sponge). A series of safety experiments with cells, blood, and tissues proved the biocompatibility of the CP-PRP sponge. Importantly, the CP-PRP sponge was able to adhere and condense red blood cells, which accelerated blood clotting. Therefore, the CP-PRP sponge showed an enhanced hemostasis effect compared to SURGIFLO® Hemostatic Matrix. Moreover, in vitro and in vivo experiments showed that the sponge was able to release epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF). Thus, in a mouse model of full-thickness skin defects, the wounds of the sponge-treated mice were significantly healed within two weeks. These results proved the transforming potential of the CP-PRP sponge as a novel bioactive wound dressing.

Chitosan-Based Hemostatic Hydrogels: The Concept, Mechanism, Application, and Prospects.

The design of new hemostatic materials to mitigate uncontrolled bleeding in emergencies is challenging. Chitosan-based hemostatic hydrogels have frequently been used for hemostasis due to their unique biocompatibility, tunable mechanical properties, injectability, and ease of handling. Moreover, chitosan (CS) absorbs red blood cells and activates platelets to promote hemostasis. Benefiting from these desired properties, the hemostatic application of CS hydrogels is attracting ever-increasing research attention. This paper reviews the recent research progress of CS-based hemostatic hydrogels and their advantageous characteristics compared to traditional hemostatic materials. The effects of the hemostatic mechanism, effects of deacetylation degree, relative molecular mass, and chemical modification on the hemostatic performance of CS hydrogels are summarized. Meanwhile, some typical applications of CS hydrogels are introduced to provide references for the preparation of efficient hemostatic hydrogels. Finally, the future perspectives of CS-based hemostatic hydrogels are presented.

An injectable anti-microbial and adhesive hydrogel for the effective noncompressible visceral hemostasis and wound repair.

An in-situ formed hemostatic hydrogel (GelMA/OD/Borax) was prepared for the emergency wound hemostasis and anti-inflammation applications. Gelatin was chosen as the backbone and modified with methacrylic anhydride (MA) to synthesize GelMA, which showed the admirable UV light activatable polymerizing ability. Aldehyde groups, which cross-linked with the -NH2 on the tissue surface and afforded the tissue adhesion, were produced by oxidizing the o-hydroxyl groups of dextran. Further, the sodium tetraborate formed dynamic boric acid ester bonds with the oxidized dextran (OD). With this triple-network structure, the as-prepared hydrogel presented excellent hemostatic capacity and surmounted a high blood pressure of 165 mmHg, which is higher than the threshold systolic blood pressure of healthy adults (i.e., 120 mmHg). The mechanical property, morphology, biocompatibility and degradation of the hydrogel were character Borax, the hydrogel successfully blocked the bleeding and accelerated the wound healing. This research provides a new modality for the design of a multifunctional hemostatic hydrogel for effective hemostasis and wound healing.

Alginate microparticles as oral colon drug delivery device: A review.

The increase in the research interest on alginate microparticles in pharmaceutical and biomedical areas confirms its potential use as an effective matrix for drug and cell delivery. Among the well known alginate properties, pH sensitivity remains as an attractive option for targeting of drug in the colon region. This essential aspect is advantageous to enhance therapeutic efficacy of treatment of inflammatory bowel diseases, which require multi-drug administration frequently in a long period. As consequence, severe side effect appears leading to discontinuation of therapy and affecting quality of patient life. This review gives an overview of relevant properties of alginate as oral colon delivery systems and the recent innovative strategies of using alginate with other polymers as well as microencapsulation techniques. At the same time, it describes the several advantages of coating processes involving alginate over microparticles in order to design better material with sustained release characteristic for colon-targeted delivery.

Incorporación de agentes antimicrobianos en formulaciones de adhesivos cianoacrílicos / Incorporation of antimicrobial agents into cyanoacrylates adhesives formulations

En la actualidad, nuevas formulaciones de los adhesivos tisulares α-cianoacrílicos, se estudian para la reparación de tejidos blandos y duros, con vistas a mejorar sus propiedades, entre las que se encuentran: biodegradabilidad, biocompatibilidad ósea, flexibilidad (en las aplicaciones a tejidos blandos), facilidad de manipulación y la esterilidad. El adhesivo Tisuacryl, en su formulación contiene cianoacrilato de n-butilo, no tiene principio farmacológicamente activo y se comercializa sin pasar por un proceso previo de esterilización. Su conservación (≤ 5 ºC) y su transportación debe estar garantizada por una cadena de frio a diferencia de productos homólogos en el mercado internacional que en su formulación contienen principios farmacológicamente activos, se conservan a temperatura ambiente y se comercializan estériles. La presente propuesta tiene como objetivo destacar la importancia dentro de una formulación cianoacrílica de un agente antimicrobiano, que actúa como inhibidor de la polimerización por vía aniónica, mejora las propiedades y amplía las posibilidades de uso del producto. Para abordar el tema, se realizó un análisis de la literatura actualizada incluyéndose revistas de alto impacto y sitios Web en Internet de un adhesivo comercial que contiene diyodometil-p-tolilsulfona como agente antimicrobiano e inhibidor de la reacción de polimerización por vía aniónica.

Currently, new formulations of tissue adhesives ?-cyanoacrylic, are studied for repair of soft and hard tissues, in order to improve their properties, among which are: biodegradability, bone biocompatibility, flexibility (in applications to tissues soft), ease of handling and tissue adhesive sterility. Cuban adhesive, Tisuacryl in its formulation contains mainly n-butyl cyanoacrylate, has not pharmacologically active ingredient and is not going through a previous process of sterilization. A cold chain unlike similar products in the international market, which in its formulation containing pharmacologically active ingredients stored at room temperature and marketed sterile, must guarantee conservation (≤ 5 ºC) and transportation. This review aims at highlighting the importance within a cyanoacrylic formulation of an antimicrobial agent, which acts as polymerization inhibitor anionically, improves properties, and extends the possibilities of use of the product. A documentary analysis of the current literature including high impact journals and websites of a commercial adhesive containing diyodomethyl-p-tolylsulphone as an antimicrobial agent and anionic polymerization inhibitor was carried out.