Polyelectrolyte capsules fabricated by layer-by-layer (LbL) technique are introduced as a simple and efficient carrier system for spontaneous deposition of proteins and low molecular water soluble drug. The objective of the work was to investigate the applicability of polyelectrolyte capsules as vehicles for sustained or controlled delivery of drugs. Two different polymeric systems composed of weak and strong polyelectrolytes were chosen to study the loading and release behavior in order to meet the requirements of biomedical applications. In the first system, the wall permeability of weak polyelectrolyte (PAH/PMA) capsules could be readily manipulated from open to closed state by simply varying the pH. The open and closed state of the capsules could be attributed to the charge density variation of weak polyelectrolytes, which induces the capsule wall to undergo a transition from continuous to nanoporous morphology due to phase segregation. Bovine Serum Albumin (BSA) was spontaneously deposited in the hollow capsules and deposition was investigated by CLSM, SEM and AFM techniques. The driving force for spontaneous deposition was electrostatic interaction between the preloaded polystyrene sulfonate (PSS) and BSA. The deposition was uniform and concentration of BSA in the capsule interior reached a few hundred times greater than that of bulk. The amount of loading was significantly influenced by the loading pH, loading concentration and charge density of substance to be loaded at the corresponding pH. The deposition was successful up to the isoelectric point of BSA (pH = 4.8) and there was no loading observed above that, since the deposition is based on electrostatic attraction between PSS and BSA. During the release at physiological pH of 7.4, charge reversal of BSA occurred which induced electrostatic repulsion between PSS and BSA thereby triggering the movement of BSA from the interior to the bulk. Release continued up to 5 h in water and a total release of 63 % was observed which increased to 72 % when release was performed in PBS. Spontaneous deposition of low molecular weight, water soluble drug, ciprofloxacin hydrochloride was performed in the same manner and its release profile was studied. Controlling diffusion of smaller drug molecules is extremely difficult in drug delivery applications. Cross linking of capsule wall components could be used to control the release rates of smaller drug molecules. Cross linking density is dependent on the cross linking time and increases the stiffness of the capsule wall. Release of ciprofloxacin hydrochloride was possible even up to 6 h after cross linking. Antibacterial studies showed that the drug released even after 25 h has a significant effect on the bacterial pathogen E.coli. The second system included weak and strong polyelectrolytes (PAH & DS) and a novel route was employed to fabricate optically addressable capsules that could be laser activated for delivery of drugs. This approach involved a combination of LbL assembly and polyol reduction method wherein PEG was used to reduce AgNO3 to Ag nanoparticles (NPs). The capsules were prepared via LbL assembly of PAH and DS on silica template followed by synthesis of silver NPs in the layers and subsequent dissolution of the silica core. The sulfonate groups of DS present in the polyelectrolyte film act as binding sites for the adsorption of silver ions which are then reduced to silver NPs in the presence of PEG. The size of the silver NPs formed was influenced by the AgNO3 concentration used. At lower concentration, smaller particles of uniform distribution were observed which turned into larger particles of random distribution when the concentration of AgNO3 is increased. Silver NPs embedded capsules ruptured when exposed to laser and was significantly influenced by silver NPs size, their distribution, laser intensity and time of exposure. The synthesis of silver NPs increased the permeability of the capsules to higher molecular weight substances like dextran caused by the defects, discontinuities and pores created on the polymeric network due to the newly formed silver NPs. Encapsulation of FITC-dextran was performed using thermal encapsulation method by exploiting temperature induced shrinking of the capsules at elevated temperatures. During heat treatment the porous morphology transformed into smooth pore free structure which prevented the movement of dextran into the bulk and hence enrichment inside the capsules. The loaded dextran was readily released when exposed to laser and the release could be controlled from linear to burst release in order to meet practical requirements in biomedical applications.

Submitted by Verena Bastos (verena@uefs.br) on 2015-07-31T13:08:58Z No. of bitstreams: 1 Inalva V. Freitas - Pr?tica da dispensa??o de medicamentos nas unidades sa?de da fam?lia de um munic?pio baiano.pdf: 947610 bytes, checksum: 2f70af4f3d1b9c02e63659a19ba4e4df (MD5) / Made available in DSpace on 2015-07-31T13:08:58Z (GMT). No. of bitstreams: 1 Inalva V. Freitas - Pr?tica da dispensa??o de medicamentos nas unidades sa?de da fam?lia de um munic?pio baiano.pdf: 947610 bytes, checksum: 2f70af4f3d1b9c02e63659a19ba4e4df (MD5) Previous issue date: 2014-03-30 / This paper studies the practice of dispensation of drugs in the Family Health Units in a city in the Brazilian state of Bahia. The objectives of this study are to analyze the practice of dispensation in the pharmacies of the Family Health Units in a city in Bahia; and to discuss the articulation of the Family Health team in the activities of drug dispensation in the Family Health units. The theoretical referential of this study is based on the comprehension of the process of labor in public health. This is a qualitative research under a critical analytical perspective, having as a field of study 08 Family Health Units in a city of the Brazilian state of Bahia. The subjects participating in the study were divided in three groups: Group I ? key informants (three); Group II ? workers (sixteen); Group III ? users (ten). The data collection techniques were systematic observation, semi-structured interviews and document analysis. Data was analyzed using content analysis. This research was approved by the Ethics in Research Committee of the Universidade Estadual de Feira de Santana (Feira de Santana State University), report number 408.270. The observation and data analysis reveals an inarticulate labor process among the subjects, with predominant hard and light-hard technologies, with focus on management activities in detriment to user-centered assistance. Salient among the difficulties in the process are the complete absence of pharmacists in the Family Health Unit pharmacies, inadequate pharmacy structure, and inadequate training of the agents responsible for dispensation, creating the difficulty in providing a quality health care service. / Estudo sobre a Pr?tica da Dispensa??o de Medicamentos nas Unidades Sa?de da Fam?lia em um munic?pio baiano. Os objetivos s?o analisar a pr?tica de dispensa??o de medicamentos nas farm?cias das unidades Sa?de da Fam?lia em um municipio baiano; discutir a articula??o da equipe Sa?de da Familia nas atividades de dispensa??o de medicamentos, nas unidades da Sa?de da Fam?lia. Seu referencial te?rico baseia-se na compreens?o de processo de trabalho na sa?de p?blica. Pesquisa qualitativa, numa perspectiva cr?tica anal?tica tendo como campo de estudo 08 Unidades de Sa?de da Fam?lia de um munic?pio do estado da Bahia, Brasil. Os sujeitos participantes do estudo foram divididos em tr?s grupos: Grupo I informantes chaves (tr?s); Grupo II trabalhadores (dezesseis); Grupo III, usu?rios (dez). As t?cnicas de coleta de dados foram observa??o sistem?tica, entrevista semiestruturada e an?lise de documentos. Para analisar os dados foi utilizada a an?lise de conte?do. A pesquisa foi aprovada pelo Comit? de ?tica em Pesquisa da Universidade Estadual de Feira de Santana, com n?mero de parecer 408.270. A observa??o e an?lise de dados revela um processo de trabalho desarticulado entre os sujeitos, predominado as tecnologias dura e leve-dura, predominando as atividades de gerenciamento em detrimento da assist?ncia centrada no usu?rio. Destaca-se entre as dificuldades a aus?ncia completa de farmac?uticos nas farm?cias das Unidades de Sa?de, estrutura inadequada das farm?cias, despreparo dos agentes respons?veis pela dispensa??o, dimensionando a dificuldade em oferecer um cuidado de qualidade em sa?de.