Pnipaam-co-aam hydrogels as carrier systems of bioactive products of pharmaceutical interest

Orientador: Priscila Gava MazzolaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Hidrogéis são compostos poliméricos de configuração tridimensional que possuem a capacidade de absorver grandes quantidades de água. É possível encontrar utilização biológica para os hidrogéis em curativos, lentes de contato, e na liberação controlada de fármacos. Hidrogéis de poli (N-isopropilacrilamida) (PNIPAAm) são termoresponsivos e estáveis. Bromelina é o conjunto de proteases obtida principalmente a partir do abacaxi. Pode atuar em processos de cicatrização e debridamento seletivo de queimaduras, além de possuir atividades anti-inflamatória e fibrinolítica. Sendo assim, a junção do hidrogel de PNIPAAm com um ativo como a bromelina pode apontar para uma aplicação na cicatrização de feridas. Este trabalho avaliou a possibilidade de tal associação a partir do desenvolvimento e caracterização do hidrogel. Os resultados obtidos mostram que o comportamento da bromelina incorporada ao hidrogel indica ação considerável e manutenção de sua atividade diante dos testes ao qual o sistema foi exposto, o que implica na possibilidade de uso terapêutico para talAbstract: Hydrogels are polymer compounds with three-dimensional configuration that have the ability to absorb large amounts of water. Biological use can be found for hydrogels in dressings, contact lenses, and controlled release of drugs. Poly (N-isopropylacrylamide) (PNIPAAm) hydrogels are thermoresponsive and stable. Bromelain is the set of proteases obtained mainly from pineapple. It can act in processes of cicatrization and selective debridement of burns, besides having anti-inflammatory and fibrinolytic activities. Thus, the junction of the PNIPAAm hydrogel with an active substance such as bromelain can point to an application in wound healing. This work evaluated the possibility of such association from the development and characterization of the hydrogel, as evidenced in chapter II of this work. The results show that the behavior of bromelain incorporated to the hydrogel indicates considerable action and maintenance of its activity in the tests to which the system was exposed, which implies the possibility of therapeutic use for thisMestradoFármacos, Medicamentos e Insumos para SaúdeMestra em Ciências1596344/2016CAPE

Poly(n-isopropylacrylamide)-co-acrylamide Hydrogels For The Controlled Release Of Bromelain From Agroindustrial Residues Of Ananas Comosus.

This works reports the purification of bromelain extracted from Ananas comosus industrial residues by ethanol purification, its partial characterization from the crude extract as well as the ethanol purified enzyme, and its application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels. Bromelain was recovered within the 30-70 % ethanol fraction, which achieved a purification factor of 3.12-fold, and yielded more than 90 % of its initial activity. The resulting purified bromelain contained more than 360 U · mg(-1), with a maximum working temperature of 60 °C and pH of 8.0. Poly(N-isopropylacrylamide)-co-acrylamide hydrogels presented a swelling rate of 125 %, which was capable of loading 56 % of bromelain from the solution, and was able to release up to 91 % of the retained bromelain. Ethanol precipitation is suitable for bromelain recovery and application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels based on its processing time and the applied ethanol prices.811719-172

Poly(N-isopropylacrylamide)-co-acrylamide hydrogels for the controlled release of bromelain from agroindustrial residues of Ananas comosus

This works reports the purification of bromelain extracted from Ananas comosus industrial residues by ethanol purification, its partial characterization from the crude extract as well as the ethanol purified enzyme, and its application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels. Bromelain was recovered within the 30–70 % ethanol fraction, which achieved a purification factor of 3.12-fold, and yielded more than 90 % of its initial activity. The resulting purified bromelain contained more than 360 U · mg−1, with a maximum working temperature of 60 °C and pH of 8.0. Poly(N-isopropylacrylamide)-co-acrylamide hydrogels presented a swelling rate of 125 %, which was capable of loading 56 % of bromelain from the solution, and was able to release up to 91 % of the retained bromelain. Ethanol precipitation is suitable for bromelain recovery and application onto poly(N-isopropylacrylamide)-co-acrylamide hydrogels based on its processing time and the applied ethanol prices8117191726CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGsem informaçã

Modified-release topical hydrogels: a ten-year review

Hydrogels are polymeric networks with tridimensional structure, which are able to load water and other substances. Such property makes hydrogels suitable for innumerous applications in biomedical field. Hydrogels are being used as raw materials in pharmaceutical formulations for more than 60 years, while significant progress is very well documented in topical use. Natural and synthetic polymers have been applied to develop smart hydrogels that respond to physiological stimuli to follow the release of the loaded bioactive ingredient. This paper discusses the most relevant polymers commonly used in pharmaceutical formulations for modified topical delivery.Authors acknowledge FAPESP (process number 2016/03444-5), CNPq and CAPES for the financial support.info:eu-repo/semantics/publishedVersio

Characterization of PNIPAAm-co-AAm hydrogels for modified release of bromelain

Thermosensitive materials, such as PNIPAAm, are considered for the development of hydrogels for controlled release, especially for topical use. Bromelain is a set of proteases found in plants (Bromeliceae family) and it is known for having several medical uses, including healing of topical wounds. The combination of PNIPAAm hydrogels and bromelain could result in a potential formulation for topical injuries. In this work, different NIPAAm hydrogels were submitted to swelling tests for 24 h. The selected formulation presented a swelling ratio of 340%, and was used for bromelain loading, reaching up to 30% of protein loading. After loading, hydrogel disks were dried and immersed in phosphate buffer (pH 7.0) for release study. Release studies pointed to an initial burst release, followed by a modified (slower) release, reaching its optimum enzymatic activity release rates at around 60 min in both temperatures (25 °C and 37 °C). Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed bromelain loading through hydrogen bonds, without interfering in intermolecular polymeric chains. Bromelain presence decreased mucoadhesion at 25 °C and increased at 37 °C; it also increases polymers crosslink, without interfering in elastic properties (drilling and resilience). Hydrogels (blank and loaded with bromelain) showed a typical behavior of crosslinked hydrogels at rheology tests, and bromelain increased storage modulus. Both hydrogels showed a significant cell death after 24 h in NIH/3T3 cell line1054854COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2016/03444-