5 research outputs found
ENCAPSULATION AND CONTROLLED RELEASE OF rh-ERYTHROPOIETIN FROM BIOPOLYMER NANOPARTICLES
Recombinant human erythropoietin (rhEPO) is a glycoprotein, which is produced commercially from Chinese hamster ovary (CHO) cells. It is used for chronic therapy of renal anemia and chemotherapy-induced anemia in cancer patients. Recent evidence suggests that rh-EPO exerts tissue protective effects via multiple mechanisms which include inhibition of apoptosis, promotion of angiogenesis and decreased inflammation. After Intra Venus (I.V.) injection, the blood concentration of rh-EPO rapidly decreases due to proteolysis with a short half-life of 8.5 h, which makes treatment expensive. It is desirable to develop an encapsulation method which will provide a controlled release of rh-EPO and maintain the desirable concentration levels in the blood for longer time. Nanoparticles encapsulated rh-EPO can also be used for direct injection to specific tissues/organs, where sustainable concentration of rh-EPO are desirable
In this thesis, we report the production of biopolymer nanoparticles (BNP) with the following methods: (a) emulsification-evaporation (b) ionotropic gelation of the biopolymer chitosan with tripolyphosphate (TPP). The nanoparticle size distribution in aqueous solution was measured using Dynamic Light Scattering system. Three different methods were used and compared for the measurement of rh-EPO concentration in PBS aqueous solution, namely, Enzyme Linked Immunosorbent Assay (ELISA), High Performance Liquid Chromatography (HPLC), and Fluorometry. A series of experiments were performed on the encapsulation of rh-EPO in chitosan biopolymer nanopartciles using the iontropic gelation method with TPP. Rates of release of rh-EPO encapsulated in chitosan-TPP nanoparticles were measured in Phosphate Buffered Saline solution (PBS).
The concentration versus time release data were used with second order diffusion equation to estimate the effective diffusivity of rh-EPO in chitosan-TPP nanoparticles. It was concluded that the chitosan-TPP biopolymer nanoparticles were the best method for the encapsulation of rh-EPO
Design and optimization of a microfluidic system for the production of protein drug loadable and magnetically targetable biodegradable microspheres
The overall goal of this dissertation was to develop a microfluidic system for the production of magnetic and non-magnetic drug-loaded polymer microspheres with narrow size distribution. The size of microspheres is a crucial parameter for their application, as the rate of drug release from the microspheres, the rate of microsphere degradation, and the microsphere biodistribution all correlate with particle size and size distribution. Conventional microsphere production methods generally lead to the formation of particles with broad size distribution. In this work, the conventional emulsification-evaporation method for the production of microspheres was miniaturized into microfluidic flow focusing system. Using a self-designed flow focusing chip, quasi-monodisperse poly (lactic acid) microspheres were prepared. The spherical shape and narrow size distribution of the initial polymer-chloroform droplets generated at the orifice were retained throughout their movement in the channels. After complete solvent removal, the droplets turned into quasi-monosized microspheres with a coefficient of variation between 2% and 16%. To better understand the influence of different parameters on droplet generation, the behavior of the disperse phase and the continuous phase were simulated in a 3D computational multiphase droplet generation model. The experimentally determined droplet sizes correlated well with the computational model and never digressed more than 17% from the simulations. The flow focusing system was then also used directly, for the first time, to produce superparamagnetic microspheres containing 15% magnetic nanoparticles. The microspheres’ thermal properties showed their suitability for magnetic hyperthermia of large tumors in cancer therapy. The microfluidic chip was then further altered into a novel device that is able to encapsulate proteins into the polymer microspheres by integrating flow focusing and passive droplet break up systems into one-chip which contained sections of differing surface properties. With this design, bovine serum albumin-loaded microspheres could be prepared with a protein encapsulation efficiency of up to 96%. The work presented in this dissertation is the first to show that a microfluidic system can be used for the continuous production of quasi-monodisperse magnetic microspheres and protein-drug-loaded polymer microspheres. These microspheres will be useful in hyperthermia treatment, diagnostic imaging, and the targeted and controlled delivery of protein based drugs.Pharmaceutical Sciences, Faculty ofGraduat
تعيين ميزان آلودگي سطح داخلي ماسک هايN95 استفاده شده توسط پرسنل درماني يک واحد مراقبت هاي ويژه در ايران به هنگام شيوع کوويد-91
Background and Objectives: Healthcare workers in the hospitals are in front line of contact with SARS-CoV-2. Then protection of healthcare workers is a critical point for maintenance of public health. Since correct use of mask and leakage of virus from the sides into the mask play an important role for mask efficiency, in this study inner surface of N95 mask with SARS-COV-2 was evaluated.
Materials and Methods: The inner surface of N95 (JSP 822ML model) masks in the health workers of an intensive care unit from Tehran for SARS-COV-2 contamination was determined. Ethics was emphasized by research license receiving, health and safety caring.SARS-COV-2 test was presented negative in studied subjects based on the heath records. All of samples was evaluated after a shift work use of mask by a sterile swab. The RNA of SARS-CoV-2 in samples was surveyed based on the real time reverse transcription-PCR.
Results: Studied intensive care unit was contaminated by eleven confirmed COVID-19. All of health workers performed health hygiene protocols and used N95 mask in a shift (12 hours) continuously. Health workers monitor patients in the distance lower than o.5 m. However, all of swab samples from inner surface of used N95 face mask were presented negative results for SARS-CoV-2 detection.
Conclusion: Due to the negative SARS-COV-2 test in subjects and results of virus detection in inner surface of masks, there are not considerable leakages into the masks. Personal protective equipment is the last suggestion in the occupational safety, continuous and correct use of N95 mask has been recommended as the most important part of health protocol for respiratory protecting against SARS-COV-2. Moreover, training of health care workers for correct use of protective mask has been recommended.
How to cite this article: Pouyakian M, Zendehdel R, Moradpour Z, Bokharaei-Salim F, Helmi-kohnehshahri M, Taherianfar Z. Inter-Surface Contamination of Utilized N95 Masks in Healthcare Workers of an Intensive Care Unit of in Iran during Covid-19 Outbreak. Irtiqa Imini Pishgiri Masdumiyat. 2021;9(3):177-82.
سابقه و هدف: پرسنل بهداشت و درمان در خط اول تماس با بیماران کووید-19 میباشند. لذا حمایت های مناسب و پیشگیرانه از پرسنل درمانی در حفظ سلامت عمومی از اهمیت بالایی برخورداراست. از آنجاییکه پوشیدن صحیح ماسک حفاظتی و نشت از حاشیههای ماسک به داخل نقش مهمی در کارآیی ماسک دارد، به همین دلیل در این مطالعه میزان آلودگی سطح داخلی ماسک N 95 استفاده شده توسط پرسنل درمانی به سارس-کووید 2 ارزیابی شد.
روش بررسی: سطح داخلی ماسک N 95 (شرکت JSP و مدل 882 ML) استفاده شده در پرسنل درمانی و مراقبتی یک بخش مراقبتهای ویژه از بیماران بستری کووید 19 در یکی از بیمارستانهای تهران برای تعیین سارس-کووید 2 ارزیابی شد. در این مطالعه ملاحظات اخلاقی همچون کسب مجوز انجام تحقیق، رعایت اصول بهداشتی و ایمنی رعایت گردید. بررسی پرونده بهداشتی پرسنل نشان داد، تست ابتلا به سارس-کووید-2 در پرسنل مطالعه شده منفی گزارش شده است. همهی نمونهها بعد از استفادهی ماسک در انتهای یک شیفت کاری با کمک سوآپ استریل تهیه گردید. شناسایی ویروس سارس-کووید-2 با استفاده از روش RT-PCR برای شناسایی RNA ویروس در نمونهها انجام شد.
یافتهها: در زمان نمونه برداری 11 بیمار قطعی مبتلا به کووید 19 در بخش مراقبتهای ویژه بستری بودند. تمامی پرسنل مراقبتی و درمانی پروتکلهای بهداشتی را به دقت رعایت نموده و ماسکها را در یک شیفت کاری 12 ساعته به طور مداوم استفاده کردند. کارکنان مراقبتی و درمانی در فواصل کمتر از 0/5 متر رسیدگیهای معمول در خصوص بیماران را انجام میدادند. بررسیهای انجام یافته نشان داد سطح داخلی هیچکدام از نمونههای تهیه شده آلوده نبود و نتایج شناسایی ویروس منفی گزارش شد.
نتیجهگیری: با توجه به منفی بودن تست ابتلا به سارس-کووید-2 در پرسنل مطالعه شده و عدم شناسایی ویروس در سطح داخلی ماسکها می توان گفت در این مطالعه احتمال نشت از حاشیهی ماسک به سطح داخلی آن قابلتوجه نمیباشد. وسایل حفاظت فردی به عنوان آخرین اقدام حفاظتی در مشاغل مطرح است ولی استفاده مداوم و صحیح از ماسک N 95 به عنوان مهمترین راهکار در پروتکلهای بهداشتی برای حفاظت از مسیر تنفسی در برابر سارس–کووید-2 پیشنهاد میگردد. همچنین توصیه میشود استفادهی صحیح از ماسکهای حفاظتی به کارکنان مراقبتهای بهداشتی آموزش داده شود.
How to cite this article: Pouyakian M, Zendehdel R, Moradpour Z, Bokharaei-Salim F, Helmi-kohnehshahri M, Taherianfar Z. Inter-Surface Contamination of Utilized N95 Masks in Healthcare Workers of an Intensive Care Unit of in Iran during Covid-19 Outbreak. Irtiqa Imini Pishgiri Masdumiyat. 2021;9(3):177-82.