Abstract Several studies have demonstrated that sugar-based nanocarriers are recommended to develop drug delivery systems since they are biocompatible and biodegradable and might improve the therapeutic index of currently used drugs by reducing their toxicity and enhancing their bioavailability. Therewith, this work studied the processing conditions to formation of a sugar-based nanocarrier denominated polymeric colloidal nanocarriers (PCN). It reports the impact of emulsifiers types and concentration, salt concentration and copolymers addition on physical stability and particle size distribution of a maltodextin-based PCN. In order to define the most stable formulation to produce the maltodextrin nanocarriers, 13 PCN formulations were evaluated in respect to kinetic stability, particle size distribution and morphology. The results demonstrated that to have a stable sugar-based PCN in silicone for at least 3 days, it is necessary to work with Poloxamer 188 as a copolymer, SF 1540 surfactant in a concentration proportional to the solid content and a salt concentration of 0.4 %.

Abstract Poly(ε-caprolactone)-block-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, triblock) and Poly(ε-caprolactone)-block-(poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide)-poly (ε-caprolactone) (PCL-PEO-PPO-PEO-PCL, pentablock) copolymers were synthesized by transesterification with reduction of PCL molecular mass, enabling fewer reactions, lower temperatures, and eliminating extensive purification steps. Free hydrophilic groups were removed from the samples by selective precipitation, and 1H-NMR, FTIR, GPC and DSC analyses characterized the structure and properties of the resulting copolymers. The detection of remaining hydrophilic groups indicates the formation of the amphiphilic block copolymers (BCPs). Further, we obtained polymeric nanoparticles with monodisperse size distribution profiles by nano-precipitation from both the triblock and the pentablock copolymers using a microfluidic device, resulting 144.6 and 188.9 nm size and 0.093 and 0.102 nm polydispersity index, respectively. The nanoparticle assembly depends on the copolymer composition, and the possibility of nanoparticle assembly corroborates to the block structure of the copolymers, and the success of this synthesis route to obtain BCPs.

RESUMO Neste trabalho, foram produzidas nanocápsulas contendo material de mudança de fase (“Phase Change Material” -PCM) por meio do processo de encapsulação via polimerização em emulsão, utilizando a cera palmitato de cetila como material encapsulado e o monômero metacrilato de metila como encapsulante, através de duas metodologias de processo distintas. A relação mássica cera/monômero também foi avaliada na produção das nanocápsulas. As amostras foram submetidas a caracterizações, com o objetivo de avaliar a estabilidade e integridade física das nanocápsulas após secagem em estufa, seu comportamento térmico (DSC), seus aspectos morfológicos (MEV), tamanho médio de partícula, conteúdo de sólidos e potencial operacional cíclico. Analisando os resultaos obtidos observou-se que tanto a metodologia de processo de produção quanto à variação da relação cera/monômero influenciaram diretamente na formação das nanocápsulas e no tamaho médio das partículas, sendo que as amostras produzidas através do Método II apresentaram melhores resultados quanto à formação das nanocápsulas com tamanho de partícula da ordem de 200 nm, com elevada relação cera/monômero e estáveis a processos cíclicos de temperatura.

ABSTRACT In this work, nanocapsules containing Phase Change Material (PCM) were produced by means of the encapsulation process via emulsion polymerization, using the cetyl palmitate wax as encapsulated material and the methyl methacrylate monomer as encapsulant, through two different process methodologies. The wax / monomer mass ratio was also evaluated in the production of the nanocapsules. The samples were submitted to characterizations, with the objective of evaluating the stability and physical integrity of the nanocapsules after drying in the stove, their thermal behavior (DSC), their morphological aspects (SEM), average particle size, solids content and cyclic operational potential. Analyzing the obtained results, it was observed that both the production process methodology and the variation of the wax / monomer ratio directly influenced the formation of the nanocapsules and the average particle size, and the samples produced through Method II presented better results regarding formation of the nanocapsules with particle size of the order of 200 nm, with high wax / monomer ratio and stable to cyclic temperature processes.

It is known that cetylpyridinium chloride (CPC) has in vitro and in vivo antifungal action against Candida albicans, with advantages over other common antiseptics. A CPC delivery-controlled system, transported in polymer nanofibers (PVP/PMMA), was developed to increase the bioavailability of the drug in contact with the oral mucosa. The objectives of this study were to determine if CPC in nanofiber has antifungal action against C. albicans, and in what concentration it must be incorporated, so that the fraction released can yield an inhibitory concentration. The nanofiber was prepared by electrospinning, and sterilized with gamma irradiation. Nanofiber disks with 0.05%, 1.25%, 2.5% and 5% CPC, with 5% miconazole (MCZ) and with no drug, as well as filter paper disks with 5% CPC, with 5% MCZ and with no drug were used in this study. A Candida albicans suspension (ATCC 90028) was inoculated in Mueller-Hinton Agar plates. The disks were placed on the plates and the inhibition zone diameters were measured 48h later. The nanopolymeric disks contracted in contact with the agar. All the concentrations of CPC incorporated in the nanofiber presented inhibitory action against C. albicans. Concentrations of 2.5% and 5% CPC presented a significant advantage over the nanofiber with no drug, proving the antifungal action of CPC. Under these experimental conditions, 5% CPC has greater inhibitory action against C. albicans than 5% MCZ, both in nanofiber and in filter paper. A modification made in the polymer to decrease the contraction rate may allow a larger inhibition zone to be maintained, thereby increasing the clinical usefulness of the polymer.

A new kind of thermo-responsive particles were prepared by the self-assembly technique, comprising poly(hydroxyvalerate-co-hydroxybutirate)-b-poly(N-isopropylacrylamide)/ (PHBHV-b-PNIPAAm) block copolymers. The hydrophilic part PNIPAAm was synthesized by Reversible Addition- Fragmentation chain Transfer (RAFT) polymerization. Particles with core-shell morphology were obtained with hydrophilic outer shells and hydrophobic inner cores. Dexametasone acetate (DexAc) was used as a model drug with an encapsulation efficiency of 77%. The release of DexAc in aqueous solution was strongly dependent on temperature, suggesting that PHBHV-b-PNIPAAm particles can be used as a thermo-responsive carrier material with external control in a drug release system.