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The aim of this study is to investigate the critical factor affecting the properties of PLGA microspheres fabricated by a solid-in-oil-in-water (S/O/W) emulsion technique with BSA as a model protein. Prior to encapsulation, the BSA microparticles were fabricated by a modified freezing-induced phase separation method. The microparticles were subsequently encapsulated into PLGA microspheres by S/O/W emulsion method, then Motic BA200 biological microscope, confocal laser scanning microscope, scanning electron microscope were used to observe the structure of S/O/W emulsion and PLGA microspheres. The protein content extracted or released from BSA microspheres was measured by Bradford protein assay method. It was found that NaCl added in the outer aqueous phase effectively suppressed material exchange between the inner and outer phase of S/O/W emulsion. Then, the structure and permeability of obtained microspheres were influenced. As a result, with the increase of NaCl concentration in the outer aqueous phase, the encapsulation efficiency of microspheres significantly increased from 60% to more than 85%, the burst release of microspheres reduced from 70% to 20%, and the particle size decreased from 103 microm to 62 microm. Furthermore, the rehydration of encapsulated protein was also retarded and then integrity of BSA was successfully protected during encapsulation process. In vitro release test showed that BSA released from PLGA microspheres in a sustained manner for more than 30 days.
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Objective To investigate the therapeutic effect on allergic rhinitis(AR)with plasma radiofrequency breaking to the ethmoidal nerve and ablating concha nasalis inferior under endoscope.Methods 98 cases with AR were included in this study,which were randomly divided into 2 groups.The treating group was treated with plasma radiofrequency breaking to the ethmoidal nerve and ablating concha nasalis inferior under endoscope,the control group was treated with microwave.Results The total and significantly effective rates were 94% and 78% in the treating group,68.8% and 39.6% in the control group.The therapeutic effect of the treating group were obviously higher than that in the control group(P＜0.01).Conclusion The therapy of plasma radiofrequency breaking to the ethmoidal nerve and ablating concha nasalis inferior in the AR treatment under endoscope had the advantage of little bleeding,no serious adverse effect and com plication,significantly effective and fine clinical application.
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OBJECTIVE@#To explore the clinical and audiological characteristics of children with congenital malformations of the external ear.@*METHOD@#One hundred and ten patients with congenital malformations of the external ear ranged from 2002 to 2006 were involved in this study. The mean age was one year and four months. The children were divided into three groups according to the appearance of the external ear. The first group consisted of 94 patients with auricle malformation and atresia of the external auditory meatus. The second group consisted of 8 patients with abnormal external auditory meatus (no atresia) and auricle malformation. The other 8 patients only with auricle malformation were included in the third group. All children underwent ABR tests, while some of these children accepted DPOAE and Acoustic-immittance measurements.@*RESULT@#(1) Severe abnormal results of ABR were observed in 79 abnormal ears (78.22%) in children of first group, while moderate or severe abnormal results of ABR were observed only in 8 opposite side ears (normal ears). (2) Sixty-two and a half percent (5 ears) of ears of the second group (8 ears) had severely abnormal ABR results. (3) Severe abnormal ABR results occurred in 44.44 percent (4 ears) of ears of the third group (9 ears). Moderate or severe abnormal results of ABR were not observed in the opposite side ears (normal ears) in second and third groups.@*CONCLUSION@#Congenital malformations of the external ear is an important factor affecting children's hearing. Auditory nerve impairment can be observed in children with congenital malformations of the external ear.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Ear, External , Congenital Abnormalities , Evoked Potentials, Auditory, Brain Stem , Hearing Disorders , Hearing TestsABSTRACT
Purpose The main purposes of our research were to: 1. set up the method of the RGDHirudin microsphere preparation; 2. set up the method to test the activity and the content of the medicine contained in the microsphere; 3. analyse the key factors on the quality of the microsphere preparation. Methods Co-poly lactic acid glycolic acid (PLGA) microsphere was prepared by a modified solvent evaporation method by a double emulsion with the use of polyvinylalcohol (PVA) as emulsification; PLGA was used as biodegradable material and dichloromethane as organic solvent. The influence of formulation factors including the W1/O on microsphere diameter distribution and yield coefficient;PVA concentration on microsphere appearance, encapsulation and yield coefficient; ultrasound on spherulization average and medicine activity; stirring speed on spherulization average and microsphere appearance; PLGA on microsphere appearance and microsphere dispersity; concentration of NaCl on encapsulation efficiency, yield coefficient and medicine content etc were studied. Results The size of all the fabricated microsphere was measured according to the several factors that affect the particle size. The average diameter was 81.38 μm, which is good for further research. The medicine content and the percent yield of all the microsphere was high, which ranged from 83. 92% - 96. 3% and 79.93% - 95.05% respectively. The encapsulation efficiency was about 23.95% - 65. 13%. We found that the concentration of the NaCl and PVA were the very important factors to the encapsulation efficiency. Physiological activity of RGD-Hirudin containing in the microsphere and the release rate of the microsphere were controlled. Furthermore, the release rate was stable. Conclusions The physiologic activity of RGD-Hirudin released from the microspheres was stable. PLGA-RGD-Hirudin microspheres were controlled released by the in vitro studies. Therefore, the in vivo experiment was well grounded.
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Aim To produce poly (lactic-co-glycolic acid) (PLGA) microspheres, containing a staphylokinase variant (K35R, DGR) with reduced immunogenecity and antiplatclet aggregation activities,which allowed the preservation of protein stability during both particle processing and drug release.Methods DGR-loaded microspheres were fabricated using a double emulsion-solvent evaporation technique. The effects of preparative parameters, such as stirring rate, polymer concentration, and the excipients of both internal and external aqueous phase (W2 ), on DGR encapsulation efficiency and microsphere characteristics were investigated. In vitro and in vivo release of DGR were conducted and the cause for instability of DGR during release was also investigated. Results Moderate ultrasonic treatment of aqueous DGR/dichloromethane mixtures caused approximately. Eighty four per cent DGR denaturation.However, the activity recovery of DGR almost amounted to 100% when 2% polyvinyl alcohol (PVA) was added into the aqueous phase. It was found that NaCl in the external water phase significantly increased DGR encapsulation efficiency. Furthermore, NaCl in the external water phase played a role in determining size and surface morphology of microsphere. In vitro release test showed a burst release of DGR from microspheres, followed by sustained release of 50% total activity over 15 days. In vivo experiments showed that DGR released from microspheres sustained 5 days. Denaturation of DGR within microspheres might be resulted from acidic microclimate. Conclusion The stability of DGR was effectively protected during microencapsulation and a relatively high encapsulation efficiency of DGR was obtained. PLGA microspheres could be an effective carrier for DGR.