Biocompatibility and biodegradation of intravitreal hyaluronan implants in rabbits

Avitabile, Teresio; Marano, Filippo; Castiglione, Francesco; Bucolo, Claudio; Cro, Melina; Ambrosio, Luigi; Ferrauto, Carmelo; Reibaldí, A.

doi:10.1016/s0142-9612(00)00169-1

Cited by 60 publications

(33 citation statements)

References 13 publications

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“…Although native HA is able to dissolve rapidly in water, benzyl esters of hyaluronan show different behaviour possibly because of the different nature of the polymer. As reported in literature [27,28] it is well known that in vitro growth factor release from HYAFF11 Ò is not observable at early (namely within 15 days) stages in physiological (pH 7) conditions. Since they are composed of hyaluronan benzyl esters, HYA-FF11 scaffolds,form a gellified network from which drug release can be controlled for long periods of time in culture medium [29].…”

Section: Growth Factor Releasementioning

confidence: 85%

Hyaluronan based porous nano-particles enriched with growth factors for the treatment of ulcers: a placebo-controlled study

Zavan

Vindigni

Vezzù

et al. 2008

J Mater Sci: Mater Med

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The present study describes the production of hyaluronan based porous microparticles by a semi-continuous gas anti-solvent (GAS) precipitation process to be used as a growth factor delivery system for in vivo treatment of ulcers. Operative process conditions, such as pressure, nozzle diameter and HYAFF11 Ò solution concentrations, were adjusted to optimize particle production in terms of morphology and size. Scanning electron microscopy (SEM) and light scattering demonstrated that porous nano-structured particles with a size of 300 and 900 nm had a high specific surface suitable for absorption of growth factors from the aqueous environment within the polymeric matrix. Water acted as a plasticizer, enhancing growth factor absorption. Water contents within the HY-AFF11 Ò matrix were analyzed by differential scanning calorimetry (DSC). The absorption process was developed using fluorescence dyes and growth factors. Immunohistochemical analysis confirmed the high efficiency of absorption of growth factor and a mathematical model was generated to quantify and qualify the in vitro kinetics of growth factor release within the polymeric matrix. In vivo experiments were performed with the aim to optimize timed and focal release of PDGF to promote optimal tissue repair and regeneration of full-thickness wounds.

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Section: Growth Factor Releasementioning

confidence: 85%

Hyaluronan based porous nano-particles enriched with growth factors for the treatment of ulcers: a placebo-controlled study

Zavan

Vindigni

Vezzù

et al. 2008

J Mater Sci: Mater Med

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“…The poly (D,L-lactide-co-glycolide) is a classic example amongst the synthetic polymers and has been well applied as drug delivery system due to its satisfactory biocompatibility and absence of significant toxicity in vivo studies 2,3 . Due to biodegradable intraocular implants nanoparticle constitution, the nanoscience can be an important tool to study their properties based on the polymer/ drug interaction analysis.…”

Section: Introductionmentioning

confidence: 99%

Development and characterization of an intraocular biodegradable polymer system containing cyclosporine-A for the treatment of posterior uveitis

et al. 2008

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The aim of this study was to synthesize and characterize the biodegradable intraocular implants based on poly (D,L-lactide-co-glycolide) (PLGA 75:25) with Cyclosporine-A (CyA) and to evaluate their in vitro drug delivery profile. Thermal analysis was conducted by using Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC). Phase analysis and crystallinity of the polymer-CyA samples were assessed through X ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Finally, microstructure and morphology of the systems were investigated by Scanning Electron Microscopy (SEM). The results showed that CyA was successfully incorporated into PLGA network with drug loading of approximately 31.6%. Also, based on FTIR and thermal analyses (TGA/DSC) no significant physical-chemical interaction was detected at the micro-nanoscale level between polymer/drug. SEM micrographs have indicated a uniform drug distribution in PLGA matrix. XRD patterns have showed that the incorporated semi-crystalline structure of CyA has not significantly altered the polymeric mainly amorphous network. In addition, the results have confirmed the chemical and biological drug stability, the drug distribution into the polymeric matrix and the possibility of cyclosporine prolonged delivery system profile.

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“…A biocompatibilidade e a biodegradação in vivo de implantes intravítreos preparados com diferentes ésteres de ácido hialurônico foi avaliada em olhos de coelhos (Avitabile et al, 2001 A segurança e a eficácia de um sistema biodegradável composto de PLGA e contendo 0,5 mg de ciclosporina (CsA) foram avaliadas após sua implantação na câmara anterior de olhos de coelhos (Theng et al, 2003 A eficácia de um implante polimérico biodegradável contendo tacrolimus foi avaliada em um modelo animal de uveíte experimental (Sakurai et al, 2003 A uveíte recorrente equina (URE), também conhecida como cegueira da lua, iridociclite e oftalmia periódica é a causa mais comum de cegueira em BIONDI, F. et al Implantes poliméricos intraoculares de fármacos na medicina veterinária, revisão de literatura e relato de um caso. PUBVET, Londrina, V. 6, N. 23, Ed.…”

Section: Desenvolvimentounclassified

“…210, Art. 1399, 2012 em severos efeitos adversos (Fialho e Cunha Júnior, 2007 Devido a todas as dificuldades encontradas, algumas pesquisas têm sido realizadas no sentido de desenvolver sistemas de administração intraoculares que permitam liberar concentrações terapêuticas dos fármacos por um período prolongado e adequado (Rubsamen et al, 1994;Hashizoe et al, 1994;Chang e Wong, 1999;Gilger et al, 2000;Avitabile et al, 2001;Okabe et al, 2003;Sakurai et al, 2003;Saliba et al, 2008;Choonara et al, 2011;Haghjou et al, 2011). Tais sistemas podem proporcionar inúmeras vantagens, como aumentar a biodisponibilidade do fármaco, no sentido de obter uma liberação constante e prolongada; aumentar as concentrações locais, sem a ocorrência de efeitos adversos sistêmicos; atingir mais especificamente um tipo de tecido ou célula; reduzir a freqüência de injeções intraoculares.…”

Section: Introductionunclassified

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2012

Pubvet

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ResumoDoenças do segmento posterior do bulbo do olho são responsáveis pela maioria dos casos de cegueira irreversível no mundo inteiro e, até o momento, BIONDI, F. et al. Implantes poliméricos intraoculares de fármacos na medicina veterinária, revisão de literatura e relato de um caso. PUBVET, Londrina, V. 6, N. 23, Ed. 210, Art. 1399, 2012 apresentam sucesso terapêutico limitado devido à dificuldade de penetração dos fármacos neste local. Na medicina veterinária, as doenças oculares crônicas apresentam frequente insucesso terapêutico por conta da frequência e via de administração, além do alto custo das medicações. Visando a obtenção de níveis terapêuticos adequados de fármacos por períodos prolongados e a diminuição de efeitos colaterais indesejados, alguns sistemas de liberação poliméricos de implantação intraocular estão sendo investigados. Eles são preparados na forma de implantes a partir de polímeros que podem ser biodegradáveis ou não biodegradáveis, e pretendem revolucionar a oftalmologia humana e veterinária, aumentando o conforto do paciente e a eficácia medicamentosa no tratamento de doenças até o momento tidas como irreversíveis por conta das dificuldades terapêuticas á elas relacionadas.Palavras-chave: doenças oculares; medicação intraocular; sistemas de liberação. Polymeric implants for intraocular administration of drugs inveterinary medicine -review of the literature and report of a case AbstractDiseases of the posterior segment of the eye are responsible for most cases of irreversible blindness, and until at the present moment, have limited therapeutic success due to the difficulty of penetration of drugs in this site. In veterinary medicine, chronic eye diseases are often frustrating to treat due to the frequency and route of administration, besides the high cost of the drugs involved. In order to obtain therapeutic levels of these drugs for prolonged periods and to promote reduction of unwanted side effects, some polymeric delivery systems designed for intraocular implantation are currently being investigated. They are prepared in the form of implants from polymers that can be classified in biodegradable or nonbiodegradable, and are aimed to revolutionize medical and veterinary ophthalmology, increasing patient comfort BIONDI, F. et al. Implantes poliméricos intraoculares de fármacos na medicina veterinária, revisão de literatura e relato de um caso. PUBVET, Londrina, V. 6, N. 23, Ed. 210, Art. 1399, 2012 and effectiveness of drugs in the treatment of diseases, which are so far regarded as irreversible because of the difficulties therapies related to them.Keywords: eye diseases; intraocular medication; systems release. INTRODUÇÃOAs doenças oculares acometem as mais diversas espécies, incluindo a espécie humana, podendo causar intenso desconforto, comprometimento da acuidade visual e, por fim, cegueira. Sabe-se que as doenças do segmento posterior do olho são responsáveis pela maioria dos casos de cegueira irreversível no mundo (Fialho e Cunha Júnior, 2007). Em seres humanos, crescem os caso...

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Biocompatibility and biodegradation of intravitreal hyaluronan implants in rabbits

Cited by 60 publications

References 13 publications

Hyaluronan based porous nano-particles enriched with growth factors for the treatment of ulcers: a placebo-controlled study

Hyaluronan based porous nano-particles enriched with growth factors for the treatment of ulcers: a placebo-controlled study

Development and characterization of an intraocular biodegradable polymer system containing cyclosporine-A for the treatment of posterior uveitis

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