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Harnessing Mesoporous Spheres - transport studies and biotechnological applicationsNg, Jovice Boon Sing January 2009 (has links)
Applications in controlled release and delivery calls for a good understanding of molecular transport within the carrier material and the dominating release mechanisms. It is clear that a better understanding of hindered transport and diffusion of guest molecules is important when developing new porous materials, e.g., surfactant templated silica spheres, for biotechnological applications. Confocal laser scanning microscopy was used to quantify the bulk release and intraparticle transport of small charged fluorescent dyes, and fluorescently-tagged neutral dextran, from mesoporous silica spheres. The time dependent release and the concentration profiles within the spheres have been used to analyze the release mechanisms using appropriate models. While the small, non-adsorbing anionic dye is released following a simple diffusion driven process, the concentration of the cationic dye varies radially within the spheres after loading. The release of the cationic dye is controlled by diffusion after an initial period of rapid release, which could be due to a significant fraction of the cationic dye that remains permanently attached to the negatively charged walls of the mesoporous silica spheres. The diffusion of dextran and the resulting flat concentration profiles could be related to the complex structural feature of the cylindrical pores close to the surface, and a possible conformational change of the dextran with the concentration. The stability and leaching of a catalytic enzyme, lipase, immobilized in hydrophobilized mesoporous support has also been quantified. Colloidal monodisperse mesoporous silica spheres were synthesized and transmission electron microscopy showed that the inner pore structure display a radially extending pores. The mesoporous spheres were used as solid supports for a lipid membrane incorporated with a multi-subunit redox-driven proton pump, which was shown to remain functional. / Synthesis, functionalisation and controlled release of mesoporous materials
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Polymer networks: modeling and applicationsMasoud, Hassan 14 August 2012 (has links)
Polymer networks are an important class of materials that are ubiquitously found in natural, biological, and man-made systems. The complex mesoscale structure of these soft materials has made it difficult for researchers to fully explore their properties. In this dissertation, we introduce a coarse-grained computational model for permanently cross-linked polymer networks than can properly capture common properties of these materials. We use this model to study several practical problems involving dry and solvated networks. Specifically, we analyze the permeability and diffusivity of polymer networks under mechanical deformations, we examine the release of encapsulated solutes from microgel capsules during volume transitions, and we explore the complex tribological behavior of elastomers. Our simulations reveal that the network transport properties are defined by the network porosity and by the degree of network anisotropy due to mechanical deformations. In particular, the permeability of mechanically deformed networks can be predicted based on the alignment of network filaments that is characterized by a second order orientation tensor. Moreover, our numerical calculations demonstrate that responsive microcapsules can be effectively utilized for steady and pulsatile release of encapsulated solutes. We show that swollen gel capsules allow steady, diffusive release of nanoparticles and polymer chains, whereas gel deswelling causes burst-like discharge of solutes driven by an outward flow of the solvent initially enclosed within a shrinking capsule. We further demonstrate that this hydrodynamic release can be regulated by introducing rigid microscopic rods in the capsule interior. We also probe the effects of velocity, temperature, and normal load on the sliding of elastomers on smooth and corrugated substrates. Our friction simulations predict a bell-shaped curve for the dependence of the friction coefficient on the sliding velocity. Our simulations also illustrate that at low sliding velocities, the friction decreases with an increase in the temperature. Overall, our findings improve the current understanding of the behavior of polymer networks in equilibrium and non-equilibrium conditions, which has important implications for synthesizing new drug delivery agents, designing tissue engineering systems, and developing novel methods for controlling the friction of elastomers.
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Light-Triggered Release of DNA from Plasmon-Resonant NanoparticlesHuschka, Ryan 05 June 2013 (has links)
Plasmon-resonant nanoparticle complexes show promising potential for light-triggered, controllable delivery of deoxyribonucleic acids (DNA) for research and therapeutic purposes. For example, the approach of RNA interference (RNAi) ‒ using antisense DNA or RNA oligonucleotides to silence activity of a specific pathogenic gene transcript and reduce expression of the encoded protein ‒ is very useful in dissecting genetic function and holds promise as a molecular therapeutic. Herein, we investigate the mechanism and probe the in vitro therapeutic potential of DNA light-triggered release from plasmonic nanoparticles.
First, we investigate the mechanism of light-triggered release by dehybridizing double-stranded (dsDNA) via laser illumination from two types of nanoparticle substrates: gold (Au) nanoshells and Au nanorods. Both light-triggered and thermally induced releases are distinctly observable from nanoshell-based complexes. Surprisingly, no analogous measurable light-triggered release was observable from nanorod-based complexes below the DNA melting temperature. These results suggest that a nonthermal mechanism may play a role in light-triggered DNA release.
Second, we demonstrate the in vitro light-triggered release of molecules non-covalently attached within dsDNA bound to the Au nanoshell surface. DAPI (4',6-diamidino-2-phenylindole), a bright blue fluorescent molecule that binds reversibly to double-stranded DNA, was chosen to visualize this intracellular light-induced release process. Illumination through the cell membrane of the nanoshell-dsDNA-DAPI complexes dehybridizes the DNA and releases the DAPI molecules within living cells. The DAPI molecules diffuse to the nucleus and associate with the cell’s endogenous DNA. This work could have future applications towards drug delivery of molecules that associate with dsDNA.
Finally, we demonstrate an engineered Au nanoshell (AuNS)-based therapeutic oligonucleotide delivery vehicle, designed to release its cargo on demand upon illumination with a near-infrared (NIR) laser. A poly(L)lysine peptide (PLL) epilayer coated onto the AuNS surface (AuNS-PLL) is used to capture intact, single-stranded antisense DNA oligonucleotide, or alternatively, double-stranded short-interfering RNA (siRNA) molecules. A green fluorescent protein (GFP)-expressing human lung cancer H1299 cell line was used to determine cellular uptake and GFP gene silencing mediated by AuNS-PLL delivery vector. The light-triggered release of oligonucleotides could have broad applications in the study of cellular processes and in the development of intracellular targeted therapies.
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Developing a Minimally Invasive Sustained Release System for Glioma TherapyKao, Chen-Yu 16 November 2007 (has links)
Malignant brain tumor is one of the most lethal forms of cancers. In the United States alone, approximately 20,500 new cases of primary malignant brain and central nervous system tumors are expected to be diagnosed in 2007 with 12,740 deaths estimated. Treatment of malignant brain tumor remains a major challenge despite recent advance in surgery and other adjuvant therapies, such as chemotherapy. The failure of potential effective chemotherapeutics for brain tumor treatment is usually not due to the lack of potency of the drug, but rather can be attributed to lack of therapeutic strategies capable of overcoming blood brain barrier for effective delivery of drug to the brain tumor. In this thesis, we developed a minimally invasive sustained release system for glioma therapy. The present study was initiated in an effort to incorporated Doxorubicin (DOX) loaded PLGA particle into an agarose gel, which can provide a continuous release of DOX locally to the tumor site. DOX, a toposiomearase II inhibitor, is not currently used clinically for brain tumor treatment because when delivered systemically it does not cross BBB. Our hydrogel particle system can overcome this shortcoming of DOX. The results from this study demonstrate that the DOX/PLGA particle gel system can maintain the bioactivity of DOX and sustained release DOX for at least 15 day in vitro. The result of in vivo study showed the DOX/PLGA particle gel treated group had significantly extend the medium survival of 9L glioma bearing rat from 21 days to 29 days. Therefore, the success experience of this local and sustained delivery device might benefit the development of future glioma therapy strategy.
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Vancomycin Containing Plla Delivery System For Bone Tissue Biocompatibility And Treatment Of Implant Related Chronic OsteomyelitisUysal, Berna 01 September 2009 (has links) (PDF)
Osteomyelitis is an infection of bone or bone marrow, usually caused by pyogenic bacteria. It can cultivate by hematogen way or it can cultivate by the help of local soft tissue infection. Osteomyelitis often requires prolonged antibiotic therapy and surgery. But for therapy / antibiotic must reach to effective dose in the bone. So that / for prevention and treatment of osteomyelitis controlled antibiotic release systems can be used. These systems have been developed to deliver antibiotics directly to infected tissue. As a carrier material / polymers are widely use. Polymer can be biodegradable or non biodegradable. The advantage of biodegradable polymers is / you do not need a second surgery for the removal of the carrier material from the body.
In this study / vancomycin loaded PLLA/TCP composites were developed and characterized to treat implant related chronic osteomyelitis in experimental rat osteomyelitis model. Some of the composites were prepared by coating the vancomycin loaded composites with PLLA to observe the difference between the coated and uncoated composites. Also, some composites were developed free from the vancomycin to determine the biocompatibility of the composite for the bone tissue. The coating extended the release of the vancomycin up to 5 weeks and changed the surface morphology of the composites. According to the cell culture studies, vancomycin loaded PLLA/TCP composites promoted cell adhesion, cell proliferation and mineralization so / the composite was biocompatible with bone tissue. Radiological and microbiological evaluations showed that vancomycin loaded and coated vancomycin loaded PLLA/TCP composites inhibited MRSA proliferation and treat implant related chronic osteomyelitis.
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Encapsulation and controlled release of active DNA from uncrosslinked gelatin microspheresHardin, James 12 December 2011 (has links)
Cancer is a disease that varies dramatically from person to person due to the specifics of the individual's physiology and the source of the cancer. In most cases, the origin of the cancer can be determined but metastasis can lead to tumors anywhere and thus many cancers require treatment of the whole body. Since many of the drugs that are used to treat cancer are toxic to healthy cells as well as cancerous ones, there has been considerable interest in developing ways to convey the drug specifically to the cancer cells with minimal exposure to healthy cells. Colloid drug delivery vehicles have shown considerable progress toward this end, while also reducing degradation of the drug prior to delivery to targeted sites (particularly important for oligonucleotide and protein therapeutics), and controlling release rates.
Toward the end of improved drug delivery, this thesis work investigates the encapsulation of DNA in gelatin microspheres (GMS) and the subsequent temperature controlled release of the encapsulated DNA from these GMS. DNA-loaded GMS were then used as templates for colloidal satellite assemblies and the released DNA was shown to competitively displace the original partner strands of immobilized DNA on the surface of the assemblies. To support these investigations, hybridization of DNA at colloidal surfaces was also investigated using in situ measurements and found to significantly deviate from solution behavior. DNA hybridization is of particular interest as means of controlling the functionality of colloidal structures because it is uniquely reversible and tunable as well as biocompatible. Gelatin was chosen as the encapsulation matrix for its superior biocompatibility, convenient gel to liquid phase transition at ~35 oC, and economical availability.
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Βιοαποικοδομήσιμο σύστημα ελεγχόμενης αποδέσμευσης ακετονικής τριαμσινολόνης για διασκληρική χορήγηση : in vitro μελέτηΜπλάτσιος, Γεώργιος 21 October 2011 (has links)
Η Ακετονική Τριαμσινολόνη είναι ένα συνθετικό γλυκοκορτικοειδές το οποίο έχει ευρέως χρησιμοποιηθεί στη θεραπεία ενός αριθμού φλεγμονωδών και αγγειακών / εξιδρωματικών παθήσεων του οφθαλμού, χορηγούμενη υπό μορφή ένεσης παραβόλβια, υποτενόνια ή ενδοϋαλοειδικά. Δυστυχώς έχει περιορισμένο χρόνο ημιζωής με συνέπεια να είναι συχνά αναγκαίες επανειλημμένες ενέσεις για να επιτευχθεί παρατεταμένη δράση. Αυτό αυξάνει τη συχνότητα των επιπλοκών, οι οποίες σχετίζονται τόσο με το ίδιο το φάρμακο όσο και με την οδό χορήγησης.
Σκοπός της μελέτης: Η παρασκευή σκληρικών συστημάτων ελεγχόμενης αποδέσμευσης Ακετονικής Τριαμσινολόνης βασιζόμενα στο βιοδιασπόμενο πολυμερές Πόλυ[γαλακτικό] (PLA) και η αξιολόγηση των in vitro/ex vivo χαρακτηριστικών τους σε σχέση με τη δυνητική χρήση τους για παρατεταμένη διασκληρική χορήγηση ΤΑ.
Υλικό και Μέθοδος: Μικροσφαίρες PLA που περιείχαν ΤΑ παρασκευάστηκαν με τη μέθοδο του απλού και του διπλού γαλακτώματος. Εξετάστηκαν η μορφολογία τους, το μέγεθός τους, η επίδραση της αρχικής ποσότητας ΤΑ και της μεθόδου παρασκευής στη φόρτιση των μικροσφαιρών καθώς και η in vitro αποδέσμευση ΤΑ από αυτές. Παρασκευάστηκαν δισκία αποτελούμενα από μικροσφαίρες καθαρού PLA και ΤΑ (με αναλογία βάρους 1:1, 2:1 και 4:1 αντίστοιχα) και εξετάστηκε η in vitro καμπύλη αποδέσμευσης ΤΑ από αυτά. Αξιολογήθηκε η καμπύλη διασκληρικής διάχυσης in vitro τοποθετώντας ένα δισκίο αναλογίας PLA:TA=1:1 σε ένα δοχείο δότη και μετρώντας τη συγκέντρωση ΤΑ σε δοχείο δέκτη. To δοχείο δότης και το δοχείο δέκτης διαχωρίζονταν διαμέσου ενός τμήματος σκληρού χιτώνα κουνελιού. Σε δύο πτωματικούς οφθαλμούς κουνελιών τοποθετήθηκε επισκληρικά ένα δισκίο 1:1 PLA-ΤΑ και καλύφθηκε με ένα σκληρικό μόσχευμα. Η συγκέντρωση της ΤΑ στο υδατοειδές υγρό και στο υαλοειδές μετρήθηκε 5, 10 και 20 ημέρες μετά από την ένθεση.
Aποτελέσματα: Η μέση διάμετρος των μικροσφαιρών ήταν 2 μm. H μέθοδος του διπλού γαλακτώματος καθώς και η αύξηση της αρχικής ποσότητας του φαρμάκου οδήγησε στην αύξηση της τιμής φόρτισης και ενκαψακίωσης των μικροσφαιρών. Παρατηρήθηκε παρατεταμένη για αρκετές μέρες αποδέσμευση ΤΑ από τις μικροσφαίρες, με το ρυθμό αποδέσμευσης να εξαρτάται από την περιεκτικότητά τους σε ΤΑ. H ΤΑ αποδεσμευόμενη από δισκία PLA-TA παρουσίασε παρατεταμένη αποδέσμευση, με το ρυθμό της να εξαρτάται από το λόγο PLA:TA. H TA μπόρεσε να διαπεράσει το σκληρό χιτώνα με περίπου 21% του φαρμάκου στο δοχείο δότη να έχει διαχυθεί διαμέσου του σκληρού χιτώνα μετά από 45 ημέρες. Μετά από σκληρική χορήγηση η ΤΑ εμφάνισε συγκεντρώσεις στο υδατοειδές υγρό και στο υαλοειδές σε πτωματικούς οφθαλμούς.
Συμπεράσματα: Οι μικροσφαίρες και τα δισκία PLA-TA που αναπτύχθηκαν σε αυτήν τη μελέτη παρουσιάζουν παρατεταμένη και ελεγχόμενη αποδέσμευση ΤΑ, έχουν τα πλεονεκτήματα της καθιερωμένης βιοαποικοδομησιμότητας και βιοσυμβατότητας του πολυμερούς PLA, παρέχουν ευελιξία ως προς το ρυθμό αποδέσμευσης και τη συνολική δόση ΤA και παρουσιάζουν ευκολία στους χειρουργικούς χειρισμούς. Αυτά τα συστήματα φαίνεται να είναι υποσχόμενα για την ελεγχόμενη διασκληρική χορήγηση ΤΑ και δικαιολογείται η περαιτέρω μελέτη τους. / Triamcinolone Acetonide (TA) is a synthetic glucocorticoid, which has been widely used to treat a number of inflammatory and vascular and/or exudative diseases of the eye, administered via a peribulbar, sub-tenon or intravitreal injection. Unfortunately, it has a limited half-life and thus repeated injections are often required to establish a prolonged effect. This increases the rate of complications, which are related to the drug itself as well as to the administration route.
Study Purpose: To develop scleral controlled-release-systems of Τriamcinolone Αcetonide based on biodegradable Poly[lactide] (PLA) and evaluate their in vitro/ex vivo properties with regard to their possible application for the prolonged transscleral delivery of TA.
Materials and Methods: PLA microspheres containing TA were prepared by a single or double emulsification-solvent evaporation method. Morphology, size, effect of drug input and method of microsphere preparation on drug loading, and in vitro TA release of the microspheres were investigated. Tablets consisting of blank PLA-microspheres and TA (weight ratios of 1:1, 2:1, and 4:1, respectively) were developed and their release profile οf TA in vitro was evaluated. The in vitro transscleral diffusion profile was evaluated by placing a PLA-TA (1:1) tablet in a donor chamber and measuring the TA concentration in a receptor chamber. Donor and receptor chambers were separated by rabbit sclera. Two cadaver rabbit eyes received a 1:1 PLA-TA tablet episclerally, which was covered by a scleral patch. TA aqueous humor and vitreous concentrations were measured 5, 10, and 20 days post implantation.
Results: Microsphere average diameter was 2 μm. The double emulsification method and increasing drug input led to an increase in microsphere drug loading and encapsulation. Sustained release of TA over several days from the microspheres in vitro was observed, with the rate of release being affected by their TA content. TA exhibited sustained release profile from the PLA-TA tablets, with the rate of release being affected by the PLA:TA ratio. TA could cross the sclera tissue in vitro, with approximately 21% of the initial drug in the donor compartment having diffused through the sclera in 45 days. Following scleral administration of the PLA-TA tablets, TA accumulated in the vitreous and aqueous humor of cadaver eyes.
Conclusions: The PLA-TA microspheres and tablets developed in this study provide a sustained and controlled release of TA, provide the advantages of established biodegradability and biocompatibility of the PLA polymer, demonstrate flexibility concerning their TA release rate and total TA dosage and are easy to surgically manipulate. These systems appear promising for the controlled transscleral delivery of TA and justify further investigation.
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Filme de quitosana para liberação controlada de colchicina para tratamento de carcinoma basocelular. / Chitosan film for controlled release of colchicine for treatment of basal cell carcinoma.BRAZ, Adriana da Costa. 13 April 2018 (has links)
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Previous issue date: 2014-12-12 / O Carcinoma basocelular é o câncer mais comum do mundo, e apesar da sua
evolução muitas vezes benigna, com altas taxas de cura, algumas vezes nos
deparamos com casos mais agressivos, invasivos, destrutivos e de difícil controle. É
sabido que já houve avanços terapêuticos para estes casos específicos, a exemplo
do Vismodegib, entretanto o uso desta droga ainda é uma realidade distante para
nossos pacientes brasileiros que se expõe a índices elevados de radiações solares,
na maioria trabalhadores rurais de baixa renda e com grande dificuldade a
acessibilidade ao sistema público de saúde. Por isso, o presente trabalho sugere
uma alternativa para o controle das formas graves do carcinoma basocelular,
através da produção de um filme de quitosana dopado de colchicina substância
sabidamente antimitótica e com evidência clínica já citada na literatura no carcinoma
basocelular, por via transdérmica por liberação controlada da droga que permita
mantê-la em um nível sérico contínuo, suficiente para sua ação antimitótica,
causando morte seletiva das células tumorais, diminuindo ou extirpando esses
tumores, com custos mais acessíveis, pois é uma droga de baixo custo, melhorando
consequentemente a morbidade da doença e a qualidade de vida destes pacientes.
E os resultados obtidos através das caracterizações apresentaram membranas com
variações de cristalinidade (por DRX) de acordo com o processo de reticulação. Por
FTIR pode-se observar certa interação entre o fármaco e os grupos amina da
quitosana. Pelas microscopias ótica e eletrônica, pode-se observar que o acréscimo
de fármaco proporcionou alguma rugosidade a membrana. Também pelas
microscopias verificou-se a reticulação não homogênea da superfície da membrana.
Por EDS não se verificou nenhum elemento estranho a estrutura da quitosana e do
fármaco. Por medida do ângulo de molhabilidade pode-se verificar aumento do perfil
hidrofílico da membrana por adição do fármaco, perfil este que foi modificado pelo
processo de reticulação. A partir do ensaio de citotoxicidade pode-se constatar que a
membrana apresenta certa citotoxicidade. Este resultado demonstra também o
potencial da membrana de quitosana em liberar o fármaco, considerando que a
membrana apenas de quitosana não apresenta toxicidade em meio biológico, sendo
a toxicidade observada no ensaio decorrente do fármaco liberado. / Basal cell carcinoma is the most common cancer in the world, and despite its
evolution often benign, with high cure rates, sometimes we are faced with more
aggressive, invasive cases, destructive and difficult to control. It is known that there
have been advances in treatment for these specific cases, such as the Vismodegib,
however this drug is still a distant reality for our Brazilian patients who are exposed to
high levels of solar radiation in most rural workers from low-income, great difficulty
accessibility to the public health system. Therefore, this study suggests an alternative
for the control of severe forms of basal cell carcinoma, through the production of a
chitosan film doped colchicine known antimitotic substance and with clinical evidence
already mentioned in the literature in basal cell carcinoma, transdermally for release
controlled drug that allows keep at a steady serum level, enough for their antimitotic,
causing selective killing of tumor cells, reducing or extirpating these tumors, with
more affordable because it is an inexpensive drug, consequently improving morbidity
the disease and the quality of life of these patients. And the results obtained from the
characterization showed membranes crystallinity variations (XRD) according to the
crosslinking process. By FTIR one can observe some interaction between the drug
and amino groups of chitosan. Through optical and electronic microscopy, it can be
seen that addition of drug has provided some roughness to the membrane. Also by
microscopy verified the inhomogeneous crosslinking of the membrane surface. EDS
there was no foreign object the structure of chitosan and the drug. By measuring the
wetting angle can be checked increase the hydrophilic profile of the drug by adding
the membrane, this profile has been modified by the crosslinking process. From the
cytotoxicity assay can be seen that the membrane has some cytotoxicity. This result
also demonstrates the potential of chitosan membrane to release the drug, whereas
only chitosan membrane shows no toxicity in biological medium, with the toxicity
observed in this trial due to the released drug.
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Obtencao de um sistema de liberacao controlada de drogas a partir do PVAL irradiado com radiacao gamaTERENCE, MAURO C. 09 October 2014 (has links)
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Membranas porosas de quitosana/gelatina para liberação controlada de insulina.MAIA, Paula Christianne Gomes Gouveia Souto. 13 June 2018 (has links)
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Previous issue date: 2015-06-19 / O estudo sobre sistema de liberação controlada de fármaco está em constante
crescimento, pois visa melhorar e prolongar o controle da administração de
fármacos. Insulina oral é um sonho dos pacientes e um desafio para os cientistas.
Para os doentes, não é apenas o alívio da dor da aplicação de múltiplas injeções,
mas também a proteção das células betas do pâncreas. A quitosana é um
biomaterial considerado atóxico, não alergênica, biodegradável, biofuncional,
biocompatível e as suas atividades biológicas compreendem a ação antioxidante,
antimicrobiana, analgésica, aceleração da cicatrização, anti-inflamatórias além de
ser muito estudada como matriz polimérica em sistemas de liberação controlada de
fármacos. A gelatina por sua vez está sendo muito utilizada na área farmacêutica
com a finalidade de favorecer o intumescimento do sistema e consequentemente
acelerar o processo de liberação. Sendo assim, este trabalho teve como objetivo
desenvolver membranas de quitosana, gelatina e insulina para uso em sistema de
liberação controlada de fármacos. As membranas desenvolvidas foram
caracterizadas pelas técnicas de Difração de raios-X (DRX), Espectroscopia na
Região de Infravermelho com Transformada de Fourier (FTIR), Microscopia
Eletrônica de Varredura (MEV) com Espectroscopia por Energia Dispersiva de raios
X (EDS) e Microscopia Óptica (MO). Na técnica de DRX verificou que o que não
ocorreu alteração significativa na cristalinidade das membranas. Com a técnica de
FTIR verificou que a gelatina, insulina e o tripolifosfato de sódio não interferiram nos
grupos funcionais de superfície da quitosana, mantendo desta forma as
propriedades da mesma. No EDS foi possível detectar os elementos químicos
característicos do material. Foi possível perceber, através das técnicas de MO e
MEV, alteração na morfologia da membrana contendo insulina, gelatina e
tripolifosfato de sódio quando comparada a de quitosana pura. Baseado nos
resultados pode-se concluir que a insulina foi encapsulada pela quitosana e que a
presença da gelatina influenciou no tamanho e forma dos poros das membranas e
que a neutralização com NaOH diminuiu a quantidade de aglomerados nas
superfícies dos arcabouços reticulados com tripolifosfato de sódio. / The study of drug controlled release system is constantly growing, it aims to improve
and extend the control of drug administration. Oral insulin is a dream of patients and
a challenge for scientists. For patients, it's not just pain relief applying multiple
injections, but also the protection of beta cells of the pancreas. Chitosan, a
biomaterial is considered non-toxic, non-allergenic, biodegradable, biofunctional,
biocompatible and their biological activities include the antioxidant action,
antimicrobial, analgesic, acceleration of wound healing, anti-inflammatory as well as
being widely studied as polymer matrix systems controlled drug release. Gelatin turn
is being widely used in the pharmaceutical field for the purpose of favoring the
system swelling and consequently accelerate the release process. Thus, this study
aimed to develop chitosan membranes, gelatin and insulin for use in controlled
release system of drugs. The developed membranes were characterized by powder
Diffraction X-ray (XRD), spectroscopy in the infrared region with a Fourier transform
(FTIR) analysis, Scanning Electron Microscopy (SEM) with Energy Dispersive
Spectroscopy X-ray (EDS) and Microscopy optical (MO). In XRD technique we found
that what was no significant change in the crystallinity of the membranes. With FTIR
technique found that gelatin, insulin and sodium tripolyphosphate did not affect the
surface functional groups of chitosan, thereby maintaining the properties thereof. The
EDS was possible to detect the characteristic chemical elements of the material. It
was possible to see, through the techniques of OM and SEM, change in morphology
of the membrane containing insulin, gelatin and sodium tripolyphosphate compared
to pure chitosan. Based on the results it can be concluded that insulin was
encapsulated by chitosan and the presence of the gelatin influence the size and
shape of the pores of the membranes and neutralization with NaOH decreased the
amount of agglomerates on the surfaces of scaffolds crosslinked with sodium
tripolyphosphate.
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