Thesis submitted in fulfilment of the requirements for the Degree of Masters of Technology: Organic Chemistry, Durban University of Technology, 2011. / One of the greatest medical challenges facing mankind is the Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) which has now become a major epidemic with more than 40 million people infected worldwide. Of equal concern is its implication in high mortality and the onset of a number of opportunist mycobacterial infections, principally tuberculosis. In spite of the discovery of some relatively effective antiretroviral (ARV) drugs such as Azido Thymidine (AZT), Nevirapine (NVP) and Efavirenz (EFV), its’ application as either a single or combinational form causes side effects by harming the bone marrow. Drug resistance is a key cause of failure for treatment of HIV infection. Hence greater interdisciplinary efforts, involving both natural and social sciences, are needed urgently to combat this HIV/AIDS pandemic. Heterocyclic nitrogen based compounds, obtained from either natural sources or synthesis are adequately documented to have increased biological activity against several diseases. Recently a study of drugs containing the naphthyridine scaffold has acquired increasing attention because of its potential against HIV/AIDS. Generally, naphthyridines demonstrate good potency in both the enzyme and cellular systems and this prompted our interest in the synthesis of naphthyridine derivatives from simple and readily available starting compounds. Furthermore we wanted to form an intermediate quinolone moiety since it has good biological potential. In this study we report the synthesis of three naphthyridine derivatives, i.e. 6-phenyl-dibenzo [b, h] [1, 6] naphthyridine, 4-methyl-6-phenyl-dibenzo [b, h] [1, 6] naphthyridine and 2- methyl-6-phenyl-dibenzo [b, h] [1, 6] naphthyridine from easily available chemicals such as aniline, ortho-toludine, para-toluidine and ethyl benzoylacetate via a five step reaction scheme using either conventional reflux, microwave irradiation or both methodologies. It was found that microwave irradiation was several folds faster than conventional reflux methodology and the yield of the product was higher. The first step of the reaction scheme is a simple condensation reaction: three acrylate derivatives, viz. ethyl-3-aniline-3-phenyl acrylate, ethyl-3-phenyl-3-(ortho-tolylamino) acrylate and ethyl-3-phenyl-3-(para-tolylamino) acrylate were synthesized by refluxing ethyl benzoylacetate in an acidified ethanolic solution with aniline, ortho-toluidine and paratoluidine respectively for three hours; the yields were 95, 87.5 and 80 % respectively. Page v In the second step, thermal cyclisation was achieved for the synthesis of three quinoline derivatives, viz. 2-phenylquinoline-4(1H)-one, 8-methyl-2-phenylquinoline-4(1H)-one and 6- methyl-2-phenylquinoline-4(1H)-one from their respective acrylates under microwave irradiation for 5 minutes at 180 °C and 250 watts; the yields were 92, 84 and 80 % respectively. In the third step of the reaction, synthesis of 4-chloro-2-phenylquinoline, 4- chloro-8-methyl- 2-phenylquinoline and 4- chloro-6-methyl-2-phenylquinoline was achieved from a mixture of POCl3 and their respective quinolines via microwave irradiation for 3 minutes at 75 °C and 150 watts and via conventional reflux for 5 hours. It was found that under microwave irradiation, the reaction occurred nearly 100 fold faster but the % yield of the product was marginally higher. The fourth step of the reaction resulted in the formation of three schiff’s base, viz. 4-(Nphenyl)- 2-phenyl-4-aminoquinoline, 8-methyl-4-(N-phenyl)-2-phenyl-4-aminoquinoline and 6-methyl-4-(N-phenyl)-2-phenyl-4-aminoquinoline from their respective quinolines via microwave irradiation for 20 minutes at 180 °C and 180 watts and via conventional reflux for 2 hours. It was found that under microwave irradiation, the reaction occurred nearly 6 fold faster and the % yield of the product was over 10 % higher. The final step of the reaction was achieved by a Vilsmeir Haack reaction and in situ base catalyzed thermal cyclisation: 6-phenyl-dibenzo [b, h] [1, 6] naphthyridine, 4-methyl-6- phenyl-dibenzo [b, h] [1, 6] naphthyridine and 2-methyl-6-phenyl-dibenzo [b, h] [1, 6] naphthyridine were synthesized from their respective schiffs base via microwave irradiation for 20 minutes at 75 °C at 120 watts and via conventional reflux for 21 hours. It was found that under microwave irradiation, the reaction occurred over 60 fold faster and the % yield of the product was over 20 % higher.The outline for the five step synthesis of the three naphthyridines is presented graphically below: Page vi Key: (a) R1= H; R2=H (b) R1 = H; R2 = CH3 (c) R1 = CH3; R2 =H Reaction Conditions: 1) conc.HCl, EtOH, 3hrs, 50 °C; 2) conc. HCl, hand stirring 10 min; 3) 180 °C, MWI, 250 watts, 5 min; 4) POCl₃, MWI, 75 °C, 150 watts, 2 min; 5) POCl₃, 100 oC, 5 hrs; 6) aniline, t-BuOH, MWI, 180 °C, 180 watts, 20 min; 7) aniline, t-BuOH, 80 °C, 3 hrs; 8) DMF, POCl₃, MWI, 75 °C,120 watts 20 minute; 9) DMF, POCl3, 100 oC, 21 hrs.

Submitted in fulfillment of the requirements of the degree of Master in Technology, Department of Biomedical Technology and Clinical Technology, Durban University of Technology, Durban, South Africa, 2016. / Introduction In Africa, use of phytotherapy for treatment of diabetes mellitus is a common form of practice. Considering the increasing burden of non-communicable diseases in South Africa efforts are directed at simple, cost effective, non-hazardous and efficient methods to treat cancer, cardiovascular diseases and diabetes. The role of phytonanotherapy is an attractive proposition for advancing new therapies. Metal nanoparticles are a possible means for delivery of such therapies. However, this requires investigation on interactions, mechanisms and therapeutic efficacy upon co-administering ethnobotanicals with metal nanoparticles and existing drug therapy in human beings. Aim The primary aim of the study was to test the in vitro antidiabetic and antibacterial activity of Ocimum sanctum (leaf extracts and flower extracts), Ocimum basilicum (leaf extracts and flower extracts), and a combination of the leaf extracts of both, and to observe whether any antidiabetic and antibacterial activity was enhanced in due to phyto-synthesised bimetallic gold-silver (Au-Ag) nanoparticles and silver nanoparticles. Methods Aqueous and ethanol extracts of O. sanctum and O. basilicum leaf and flowers alone and combined (leaf + flower) were prepared using hot vs cold water extraction techniques and 60% and 70% ethanol as polar solvents. A simple, rapid, cost effective and reproducible green chemistry method synthesised alloyed bimetallic (Au-Ag) nanoparticles using O. basilicum leaf and flower aqueous extracts and prepared silver nanoparticles (AgNps) using O. basilicum and O. sanctum leaf aqueous extracts singly and in combination (O. sanctum + O. basilicum). The size, shape and elemental analysis of the nanoparticles was carried out using UV-Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDX), dynamic light scattering (DLS) and zeta potential. Fourier transform infrared spectroscopy (FT-IR) supported by gas chromatography mass spectroscopy (GC-MS) identified the bio-capping agents. Antidiabetic carbohydrate metabolising enzymes, α-amylase (porcine) and Bacillus stearothermophilus α-glucosidase as models tested the in vitro inhibitory potential of the aqueous and ethanol plant extracts and the phyto-synthesised (Au-Ag) bimetallic and AgNps. In addition, the study investigated the antibacterial potential for the aqueous plant preparations and their respective phyto-synthesised bimetallic and AgNps against the bacterial species Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella species and Pseudomonas aeruginosa compared to gentamycin and vancomycin. Results Bimetallic nanoparticles (synthesised from leaf and flower aqueous extracts) displayed inhibitory activity that showed uncompetitive inhibition (leaf extract), and non-competitive inhibition (flower extract) of α-amylase and competitive (leaf extract) and uncompetitive inhibition (flower extract) of α-glucosidase. Bimetallic nanoparticles were higher in inhibitory activity than acarbose and the crude O. basilicum ethanol and aqueous leaf and flower extracts. In the antibacterial analysis, bimetallic nanoparticles derived from O. basilicum leaf showed inhibition against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa and were greater in activity compared to the crude aqueous leaf extract from O. basilicum. The in vitro inhibitory effect of AgNps derived from O. sanctum and AgNps derived from O. basilicum on both enzymes was higher in activity than acarbose and their respective crude extracts. However, in combination (O. sanctum + O. basilicum), the derived AgNps appeared to be a less potent inhibitor of α-amylase and α-glucosidase enzyme and was lower than acarbose. AgNps synthesised from the combination of O. sanctum and O. basilicum showed the highest percentage inhibition against Bacillus stearothermophilus α-glucosidase, and AgNps derived from O. sanctum and AgNps derived from O. basilicum displayed competitive type of inhibition. In the antibacterial analysis, AgNps derived from the various extracts showed zones of inhibition against the Gram negative and Gram positive bacterial test strains. However, AgNps synthesised from the O. sanctum leaf extract showed higher inhibition against Escherichia coli than the positive control gentamycin and higher inhibition against Staphylococcus aureus compared to vancomycin. In addition, AgNps from O. sanctum leaf extract displayed inhibition against Bacillus subtilis, Pseudomonas aeruginosa and Salmonella species, thus representing the highest antibacterial potential. Conclusion The results demonstrate the possibility of synthesis of stable silver and bimetallic nanoparticles of Ocimum sp. The synthesised silver nanoparticles and first time synthesis of bimetallic (Au-Ag) nanoparticles displayed enhanced antihyperglycaemic properties compared to their respective crude extracts and, therefore, show promising effects in lowering postprandial hyperglycaemia in diabetic patients with dual potential for antibacterial treatment. However, the antidiabetic and antibacterial effect will need to be further affirmed in a clinical context. Medicinal plants with therapeutic value may create a new platform for further research to explore the potential for herbal medicine and nanoscience as effective biomedical and industrial applications, and for improving existing drug delivery systems in diabetic patients. Investigations into the cytotoxicity of these extracts and phytosynthesised nanoparticles is recommended. / M

<p>In recent years, antibacterial surfaces have been a subject of increased interest. Especiallyinteresting are non-leaching, contact-active surfaces that physically disrupts the bacterialcell using immobilised cationic polymers. Thus the risks of bacterial resistance and discharge of hazardous biocides is minimised. The assembly of such surfaces is elaborate andusually involves organic solvents. Here, polyelectrolyte multilayers (PEM) are proposed as an effective surface modification method, with an overall goal of producing antibacterial cellulose fibres. The PEM process is based on physical adsorption of oppositely charged polymers in aqueous solutions. Multilayers were formed with the bactericidal polymer polyvinylamine (PVAm) and polyacrylic acid. PVAm compounds with hydrophobic modificationswere applied as well, as they possess increased antibacterial activity in solution.</p><p>In this work, the multilayer formation was studied on model surfaces of silicone oxide and glass in order to obtain fundamental knowledge of the polymer system. QCM-D and reflectometry, which detect total mass including bound water and polymer mass only, respectively, were used to analyse the layer formation. Salt-concentrations were varied at 1, 10 or 100 mM NaCl. A stepwise multilayer formation with exponential-like polymer adsorption but with decreasing water content for each layer was seen at all salt concentrations.A higher salt concentration resulted in an increased adsorbed mass. No significant differences in adsorption between the modified and unmodified PVAm could be detected. AFM imaging applied to multilayers having nine layers showed large surface aggregates under high salt conditions for the C6-modified PVAm. Dynamic light scattering showed that the polymer occurred as single molecules in solution; hence it was concluded that theaggregation is surface-associated.</p><p>The multilayers were then tested for bacterial growth inhibition. The relative bacterial inhibition was time-dependent, as the surface was saturated with bacteria over time. After two hours, a maximal inhibition of 99 % could be observed for the multilayers. After eight hours, a moderate inhibition of less than 40 % was detected. Using multilayers affected the results positively compared to single layers. After three layers, though, no further reductionwas seen. Viability staining of the surface-adhered bacteria revealed that the adhered bacteria had intact membranes. Therefore, the microbiological properties of the multilayers can at this point be described more as growth-inhibiting by bacterial adhesion effectsthan as biocidal. However, this work has shown the importance of combining surface characterisation and microbial testing to understand the bacteria-surface interaction.</p> / Biointeractive fibres

Mini-dissertation submitted in partial compliance with the requirements of the Master's Degree in Technology: Homoeopathy, Durban Institute of Technology, 2002. / The purpose of this study was to determine the effect that Tulbagia violacea ethanolic herbal tincture, and Tulbagia violacea IX and 6X homoeopathic potencies, had 011 the in vitro growth inhibition of Escherichia coli, Klebsiella pneumoniae, Staphylococcus ourens. Pseudomonas aeruginosa and Bacil/us cereus respectively, as compared to a ethanol negative control. The final results were expressed as a ratio to the values obtained from gentamyein and vancomycin. Measurement was by means of the discdiffusion assay. For this study fifteen Mueller-Hinton agar plates were prepared and inoculated with each test bacteria in turn. Filter paper discs were individually inoculated with the sample substances and the control using a micropipette, before being allowed to air dry, One disc each of the Tulbagia violacea herbal tincture, 1X potency, 6X potency, ethanol control, as well as a gentamyein and vancomycin disc were placed equidistantly apart on each plate, The gentamyein and vancomycin discs were included in the experiment with the sole purpose of accounting for plate-to-plate variations in the pharmacological sensitivity of the same species of bacteria, The plates were incubated at 37\xB0C, and the zones of inhibitions measured with a pair of Vernier callipers at ] 8 hour, 24 hour and 36 hour intervals. Il Data entry and analysis was done using the SPSS\xAE statistical package, The Friedman test was used for intra-group comparison of each test or control substance at 18 hours, 24 hours and 36 hours. The Mann-Whitney U test was used to compare the mean inhibition zones produced by the test and control substance after 18 hours, 24 hours and 36 hours of incubation. The tests were performed at a=O.05 (5%) level of significance, The results obtained were that the Tulbagia violacea herbal tincture, and IX and 6X nomoeopathic potencies did not produce a statistically significant inhibitive effect on / M

Charles University in Prague Faculty of pharmacy in Hradec Králové Department of Biological and Medical science Candidate: Magdaléna And lová Supervisor: Mgr. Marcela Vejsová, Ph.D. Name of diploma thesis: Evaluation of activity of potentional antibacterial substances throught of the use microdilution broth metod Background Aim of this diploma work was research of activity of potentional antimicrobiotic substances. Research of antibacterial substances is one of the most important factor in pharmaceutic industry. The main reason is being the never stopping growth of bacterial resistence. Methods The microdilution broth metod was used to test the substances. This metod was used because of low difficulty and low cost. All the steps including the final analising was done by hand. Results The substances were divided in groups depending their chemical struction. The most effective was the salicylanilide derivates group. The other groups inhibitated growth of bacteria very little or were non-functional. In case of every bacterial stems were analised all substances which were effective. Conclusion Depending on the results the most sensitive and the most resistant bacterial stem were choosen. The most sensitive reaction on tested substances had bacterial stem Staphylococcus aureus. The Klebsiella pneumoniae...

>Magister Scientiae - MSc / Nanotechnology has emerged as a promising field in the quest to address health conditions. Green nanotechnology is a fairly new branch of nanotechnology, which aims to produce and utilize nanomaterials in a way that is safe for living organisms and their environment. Plant extracts are increasingly used in the green synthesis of gold nanoparticles (AuNPs), which involves the reduction of sodium tetrachloroaurate (III) dehydrate by phytochemicals present in the plant extract. It is probable that the green synthesised AuNPs are more biocompatible than chemically synthesised AuNPs as biomolecules of plant origin are involved in the synthesis process. Therefore, this study aimed to explore various water extracts from indigenous South African plants, which included Perlagonium capitatum, Otholobium bracteolatum, Gerbera linnae, Morrella quercifolia, Searsia lucida, Phylica bubescens, Euclea racemosa, Tetragonia fruticosa, and Searsia glauca for their potential to synthesize AuNPs and to investigate their toxicity towards several microorganisms known to cause skin infections. These organisms play a significant role in delaying the healing of wounds. The antimicrobial properties of nanoparticles are increasing exploited in the production of wound treatments.

O objetivo deste trabalho foi produzir hidroxiapatita (HA) contendo diferentes tipos de própolis de origem brasileira e avaliar a possível atividade antimicrobiana dos materiais. Os extratos etanólicos de própolis (EEP) vermelha, verde e marrom foram obtidos em solução alcoólica 80%. EEP verde e vermelha (8 mg/mL e 20 mg/mL) foram incorporados ao material a 10% (m/v) via atomização (spray drying), obtendo-se HA-GP8, HA-GP20, HA-RP8 e HA-RP20. Os EEP e os materiais foram caracterizados quanto ao conteúdo de compostos fenólicos e flavonoides totais. A atividade antimicrobiana dos EEP foi avaliada por difusão em ágar, concentração inibitória mínima (CIM) e bactericida mínima (CBM) frente à Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) e Escherichia coli (E. coli). Os pós de HA incorporados com própolis foram avaliados frente à S. aureus por contagem de colônias bacterianas em placa, CIM e CBM. A caracterização dos materiais foi realizada por difração de raios X (DRX), espectroscopia na região do infravermelho com transformada de Fourier (FTIR) e microscopia eletrônica de varredura (MEV). A citotoxicidade foi determinada pelo cálculo da viabilidade celular, realizada pelo método de incorporação do vermelho neutro. Para os extratos, o conteúdo de fenólicos variou entre 278,3 e 325,6 mg EAG/g ES. EEP vermelha mostrou maior conteúdo de flavonoides (112,4 mg EQ/g ES) em relação aos outros EEP (48,4 e 52,3 mg EQ/g ES), apresentando maior atividade inibitória (CIM) frente à S. aureus e S. Epidermidis (12,5 &micro;g/mL), comparado ao EEP verde (100 e 200 &micro;g/mL) e marrom (200 &micro;g/mL). Para CBM, os EEP vermelha e verde foram mais efetivos (800 &micro;g/mL) comparado ao EEP marrom (1600 &micro;g/mL), frente às mesmas bactérias. Entretanto, não foi observada atividade frente à E coli. A caracterização dos pós incorporados ou não com própolis apresentou estrutura cristalina e morfologia aparentemente esférica, indicando diminuição no grau de aglomeração com a adição de própolis. FTIR indicou a presença de grupos funcionais característicos para HA e própolis. Os materiais apresentaram alta liberação de fenólicos (228,3 a 327,6 mg EAG/g ES) e menores quantidades de flavonoides (14,0 a 35,8 mg EQ/g ES), sendo as maiores quantidades de flavonoides atribuída à HA contendo própolis vermelha. Foi verificado efeito bactericida a partir de 0,5 h (HA-RP20 e HA-GP20) e 1 h (HA-RP8 e HA-GP8) e menor atividade inibitória (CIM) para HA-GP20 e HA-GP8 (175,4 e 182,0 &micro;g/mL) e para HA-RP20 e HA-RP8 (51,7 e 66,8 &micro;g/mL), comparado aos EEP. Entretanto, observou-se maior atividade bactericida (CBM) para HA-GP20 e HA-GP8 (701,5 e 728,0 &micro;g/mL) e para HA-RP20 e HA-RP8 (206,5 e 267,0 &micro;g/mL), em relação aos EEP. O ensaio de citotoxicidade mostrou valores para IC50 (concentração que reflete 50% da viabilidade celular) de 387,1 e 84,8 &micro;g/mL para as amostras HA-GP8 e HA-RP8, respectivamente. Considerando os resultados obtidos neste trabalho, sugere-se que a HA incorporada com própolis (HA-GP8 e HA-RP8) pode ser utilizada como possível agente antimicrobiano, inibindo o crescimento de S. aureus, respeitando-se os valores máximos para IC50. Entretanto, não poderia ser utilizada como agente bactericida, uma vez que nestas condições os materiais apresentaram efeito citotóxico. / The aim of this study was to produce hydroxyapatite (HA) containing different types of propolis of Brazilian origin and to evaluate the possible antimicrobial activity materials. The ethanolic extracts of red, green and brown propolis (EEP) were obtained in alcoholic solution 80%. Green and red EEP (8 mg / mL and 20 mg / mL) were incorporated into the 10% (m/v) via atomization (spray drying), obtaining HA-GP8, HA-GP20, HA-RP8 and HA -RP20. EEP and materials were characterized regarding the content of phenolic compounds and total flavonoids. The antimicrobial activity of the EPS was evaluated by diffusion in agar, minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) against Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) and Escherichia coli (E. coli). The HA powders incorporated with propolis were evaluated against S. aureus by plate colony counting , CIM and CBM. Materials characterization was made by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The cytotoxicity of the materials was determined by cell viability calculation, which was made by the neutral red incorporation method. For extracts, phenolic content ranged from 278.3 to 325.6 mg EAG/g ES. The red EEP showed a higher flavonoid content (112.4 mg EQ/g ES) than the other EEP (48.4 and 52.3 mg EQ/g ES), showing a higher inhibitory activity (MIC) against S. aureus and S. epidermidis (12.5 &micro;g/mL) compared to green EEP (100 and 200 &micro;g/mL) and brown (200 &micro;g/mL). For CBM, red and green EEP were more effective (800 &micro;g/mL) compared to brown EEP (1600 &micro;g/mL) against the same bacteria. However, no activity was observed against E coli. The characterization of the powders incorporated or not with propolis presented crystalline structure and apparently spherical morphology, indicating a decrease in the degree of agglomeration with the addition of propolis. FTIR indicated the presence of functional groups characteristic for HA and propolis. The materials presented high phenolic release (228.3 to 327.6 mg EAG/g ES) and lower amounts of flavonoids (14.0 to 35.8 mg EQ/g ES), with the highest amounts of flavonoids attributed to HA containing red propolis. The bactericidal effect for all materials was observed within the interval of 0.5 (HA-RP20 and HA-GP20) to 1 hour (HA-RP8 and HA-GP8). The materials showed lower inhibitory activity (MIC) for HA-GP20 and HA-GP8 (175, 4 and 182.0 &micro;g/mL) and for HA-RP20 and HA-RP8 (51.7 and 66.8 &micro;g/mL) compared to EEP. However, higher bactericidal activity (MBC) was observed for HA-GP20 and HA-GP8 (701.5 and 728.0 &micro;g/mL) and for HA-RP20 and HA-RP8 (206.5 and 267.0 &micro;g/mL) when compared to the EEP. The cytotoxicity assay showed values for IC50 (concentration that reflects 50% of cellular viability) of 387.1 and 84.8 &micro;g/mL for HA-GP8 and HA-RP8 samples, respectively. Considering the results obtained in this work, it is suggested that HA incorporated with propolis (HA-GP8 and HA-RP8) can be used as a possible antimicrobial agent, inhibiting the growth of S. aureus, respecting the maximum values for IC50. However, it could not be used as a bactericidal agent, since under these conditions the materials had a cytotoxic effect.

Platonia insignis Mart. é uma espécie pertencente à família Clusiaceae, é popularmente conhecida como Bacuri e muito conhecida por ter um fruto de sabor apreciado. A utilização etnobotanica está relacionada à utilização do extrato do óleo de suas sementes como cicatrizante e anti-inflamatório e na produção de sabão. Atualmente diversas atividades vêm sendo relatadas para todas as partes deste fruto (semente, casca e polpa). Este trabalho teve como objetivo analisar o perfil fitoquímico, atividade antimicrobiana do extrato das folhas de Platonia insignis Mart. e desenvolver formulações farmacêuticas com ação antimicrobiana. A análise fitoquímica do extrato mostrou a presença de fenóis (taninos condensados, catequinas e flavonoides), esteroides, alcaloides e saponinas. As análises por LC-MSn forneceram os perfis de fragmentação dos compostos presentes no extrato. Na fração acetato de etila, foi identificado a fukugentina (morelloflavona) um importante marcador da família Clusiaceae. O extrato apresentou potencial antioxidante com inibição de 88,06% do radical DPPH. O sabonete, o creme e a solução tópica manipulados a partir do extrato a 1 e a 5% tiveram sua estabilidade analisadas no tempo zero e trinta dias após formulados, além da avaliação do controle de qualidade microbiológico. A avaliação da atividade antimicrobiana foi realizada pela técnica de microdiluição em caldo; o extrato hidroetanolico (70%), as frações hexânica, acetato de etila e os produtos manipulados apresentaram atividade antimicrobiana com CIM entre 0,78 e 12,5 mg/mL frente a todos os microrganismos testados exceto as frações orgânicas (acetato de etila e hexânica) que não apresentaram atividade frente Acinetobacter baumannii. A toxicidade avaliada pela técnica de hemólise não demonstrou atividade hemolítica até concentração testada de 100mg/mL. A toxicidade frente Artemia salina demonstrou que o extrato apresentou DL50 de 42,6 μg/mL sendo classificado como altamente tóxico frente Artemia salina. O extrato possui atividade antioxidante, microbicida e baixa toxicidade in vitro. As formulações farmacêuticas mostraram-se potencialmente viáveis no desenvolvimento de novos produtos para o tratamento de doenças infeciosas. / Platonia insignis Mart. is a species belonging to Clusiaceae, is popularly known as Bacuri and is well-known for having a fruit of appreciated flavor. The ethnopharmacological use is related to the use of the oil of its seeds in the healing of scars and as an anti-inflammatory and in the production of soap. Currently, several activities have been reported for all parts of this fruit (seed, bark and pulp). This work aimed to analyze the phytochemical profile, biological, and antimicrobial activity of the leaf extract of Platonia insignis Mart., and develop pharmaceutical formulations. Phytochemical analysis of the extract showed the presence of phenols, condensed tannins, catechins, steroids, alkaloids, flavonoids and saponins. Analyzes by LC-MS and FIA-ESI-IT/MSn provided the fragmentation profiles of the compounds present in the extract and their structures were proposed. In the ethyl acetate fraction, fukugentin (morelloflavone) was identified as an important marker of the clusiaceae family. The extract presented antioxidant potential in the inhibition of 88,06% of the DPPH radical. The soap and the topical solution manipulated from the 1 and 5% extract had their stability analyzed at time zero and thirty days after formulations, besides the evaluation of the microbiological quality control. The antimicrobial activity was evaluated by the microdilution technique. The hydroethanolic extract (70%), the hexane, ethyl acetate and the manipulated products presented antimicrobial activity with MIC between 0.78 and 12.5 mg/mL to all the microorganisms tested except the organic fractions (ethyl acetate and hexane) that showed no activity against Acinetobacter baumannii. The toxicity evaluated by the hemolysis technique did not demonstrate hemolytic activity up to a concentration of 100 mg/mL. Toxicity to Artemia salina showed that the extract had LD50 of 42.6 μg/mL being classified as highly toxic against Artemia salina. The extract has antioxidant activity, microbicide and low in vitro toxicity. Pharmaceutical formulations have proved potentially viable in the development of novel products for the treatment of infectious diseases.

Desde a década de 90 que estudos relacionados com os polímeros quitina e quitosana têm sido estimulados. A presença em maior quantidade de grupos NH2 na quitosana permite sua aplicação como biomaterial eficiente no carreamento de fármacos e na adsorção de cátions metálicos. Neste trabalho foram preparados filmes e microesferas de quitosana para uso em procedimentos de adsorção de íons prata, liberação de fármaco e atividade antibacteriana. O polímero apresentou grau de desacetilação correspondente a 81% e ponto de carga zero em pH~7. As microesferas obtidas apresentaram um diâmetro médio de 2,911 mm e um desvio padrão de 0,325, quando úmidas. O uso da quitosana na forma de microesferas e filmes proporciona um aumento da área superficial, além de facilitar o manuseio do polímero. Os filmes obtidos foram formados com nanopartículas de prata em etapa única. O melhor pH para o estudo de adsorção de íons Ag+ em meio aquoso está na faixa de pH de 5 a 7, o melhor ajuste foi ao modelo de Langmuir, o tempo ótimo para ocorrer adsorção máxima foi de 10 horas e o valor de energia aparente de adsorção (E) de 6,9 kJ/mol, o que a caracteriza adsorção física. O estudo de liberação de ibuprofeno foi realizado em fluido gástrico simulado e fluido intestinal simulado, a maior liberação do fármaco ocorreu no pH neutro dos fluidos intestinais. A liberação transdérmica de fármaco pelos filmes foi realizada apenas em pH=7,4 para simular o tecido sanguíneo e o ápice da liberação de ibuprofeno ocorreu logo no início do contato do material com o fluido simulado. As microesferas e os filmes com nanopartículas de prata demonstram ter atividade contra E. coli e S. aureus. / Since the 1990s studies related to chitin and chitosan polymers have been stimulated. The presence of more NH2 groups in chitosan allows its application as an efficient biomaterial without drug loading and adsorption of metallic cations. In this work, chitosan films and microspheres were made for use in silver ion adsorption procedures, drug release and antibacterial activity. The polymer showed a degree of deacetylation corresponding to 81% and zero loading point at pH ~ 7. As obtained microspheres had a mean diameter of 2911 mm and a standard deviation of 0.325, when used. The use of chitosan in the form of microspheres and films provides an increase of the surface area, besides facilitating the handling of the polymer. The films were formed with single step silver nanoparticles. The best pH for the Ag+ ion adsorption study in the aqueous medium is in the pH range of 5 to 7, the best fit for the Langmuir model, the optimal time for the maximum adsorption of 10 hours and the apparent energy value of adsorption (E) of 6,9 kJ / mol, which characterizes it physical adsorption. The study of ibuprofen release was performed in simulated gastric fluid and simulated intestinal fluid, further release of the drug occurs no neutral pH of intestinal fluids. Transdermal delivery of drug by films was performed at pH = 7.4 to simulate blood tissue and the apex of ibuprofen release occurred early in contact with the simulated fluid material. As microspheres and films with silver nanoparticles they demonstrate activity against E. coli and S. aureus.

Antibacterial agent delivery is of great importance in medicine and dentistry since the bacterial infections are still one of the major reasons for hospitalization and mortality. Despite of the development of technique and pharmacy, more antimicrobial agents are optimized and utilized to treat infections, and their action of principal is better understood which lay a foundation for developing strategies for infection treatment. Over the last decades, many delivery systems have been established to deliver bacterial agents and maintain a sustained activity against them. However, the bacteria are always developing and finding a way to defend themselves. A more responsive antibacterial agent delivery system, which can release the active substances on demand to match the stages of diseases, is highly desirable. Therefore, it motivates us to carry out the work to develop a multifunctional delivery system for antibacterial particle formulation and encapsulation based on the layer-by-layer self-assembly technique and electrospinning, to manipulate the release with external triggers, such as near-infrared (NIR) light and alternating magnetic field (AMF). Strategically, two different kinds of antibacterial agents, chlorhexidine and doxycycline, were studied. Chlorhexidine was fabricated into spherical particles and functionalized with both gold and magnetite nanoparticles, and doxycycline was encapsulated within microcapsules which were also functionalized with magnetite nanoparticles. Their release kinetics and possibilities to trigger the release with either a NIR light or AMF was explored. The first two chapters of the thesis give a general introduction and literature review on the current use of antibacterial agents and the problems concerned, strategies already developed for antibacterial agent delivery, and the potential triggers to induce a smart release. In chapter 3, a brief description of materials and methods, and instruments is presented. Chapter 4 is about chlorhexidine particle formulation. Firstly, particulation of chlorhexidine and mechanism of 4 spherical interconnected structure formation was explored, and then the chlorhexidine particles are encapsulated either by LbL assembly or spray-drying. The chlorhexidine spheres were also functionalized with gold nanorods and Fe3O4 nanoparticles to achieve NIR light and magnetic field manipulated release, and the effect of nanoparticles on the formation of chlorhexidine spheres was also studied. When the chlorhexidine particles were incorporated into electrospun fibers, a sustained antibacterial activity was demonstrated. Chapter 5 is about the delivery of doxycycline to cells with microcapsules and the sustained intracellular doxycycline activity was demonstrated via EGFP expression when the cells were engineered with a tetracycline regulated gene expression system. Intracellular triggered release and upregulation of EGFP expression was achieved by an AMF. The results successfully demonstrated the possibility of chlorhexidine and doxycycline delivery and NIR light/AMF triggered release, which is promising for a future application in medicine and dentistry.