Electrospun regenerated silk fibroin is a promising biomaterial for the maintenance of inner ear progenitors in vitro

2021 ◽  
pp. 088532822110515
Author(s):  
Guangfei Li ◽  
Yanbo Yin ◽  
Yaopeng Zhang ◽  
Jingfang Wu ◽  
Shan Sun
Keyword(s):  
Inner Ear ◽  
Silk Fibroin ◽  
Hair Cells ◽  
Engineering Research ◽  
Cell Mortality ◽  
Regenerated Silk Fibroin ◽  
Significant Difference ◽  
Student’S T ◽  
New Strategies

Objective We sought to determine the biocompatibility of electrospun regenerated silk fibroin (RSF) mats with inner ear progenitors, especially their effect on the differentiation of inner ear progenitors into hair cells. Methods Neonatal mouse cochleae (n = 20) were collected and digested and allowed to form spheres over several days. Cells digested from the spheres were then seeded onto aligned or random RSF mats, with laminin-coated coverslips serving as controls. The inner ear progenitor cell mortality was examined by TUNEL labeling, and the adhesion of cells to the RSF mats or coverslip was determined by scanning electron microscopy. Finally, the number of hair cells that differentiated from inner ear progenitors was determined by Myosin7a expression. Unpaired Student’s t-tests and one-way ANOVA followed by a Dunnett’s multiple comparisons test were used in this study ( p < 0.05). Results After 5 days of culture, the inner ear progenitors had good adhesion to both the aligned and random RSF mats and there was no significant difference in TUNEL+ cells between the mats compared to the coverslip ( p > 0.05). After 7 days of in vitro differentiation culture, the percentage of differentiated hair cells on the control, aligned, and random RSF mats was 2.5 ± 0.5%, 2.7 ± 0.4%, and 2.4 ± 0.2%, respectively, and there was no significant difference between Myosin7a+ cells on either RSF mat compared to controls ( p > 0.05). Conclusion The aligned and random RSF mats had excellent biocompatibility with inner ear progenitors and helped the inner ear progenitors maintain their stemness. Our results thus indicate that RSF mats represent a useful scaffold for the development of new strategies for inner ear tissue engineering research.

scholarly journals Bone marrow mesenchymal stem cells are progenitors in vitro for inner ear hair cells

2007 ◽  
Vol 34 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Sang-Jun Jeon ◽  
Kazuo Oshima ◽  
Stefan Heller ◽  
Albert S.B. Edge
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Inner Ear ◽  
Hair Cells ◽  
Marrow Mesenchymal Stem Cells

scholarly journals Emulsion of Chloramphenicol: an Overwhelming Approach for Ocular Delivery

Folia Medica ◽  
2017 ◽  
Vol 59 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Kalpesh C. Ashara ◽  
Ketan V. Shah
Keyword(s):  
Ternary Phase Diagram ◽  
Ex Vivo ◽  
Sterility Testing ◽  
Ocular Irritation ◽  
Peg 400 ◽  
Significant Difference ◽  
Oil Mixtures ◽  
Student’S T ◽  
The Impact

Abstract Background: Ophthalmic formulations of chloramphenicol have poor bioavailability of chloramphenicol in the ocular cavity. Aim: The present study aimed at exploring the impact of different oil mixtures in the form of emulsion on the permeability of chloramphenicol after ocular application. Materials and methods: Selection of oil mixture and ratio of the components was made by an equilibrium solubility method. An emulsifier was chosen according to its emulsification properties. A constrained simplex centroid design was used for the assessment of the emulsion development. Emulsions were evaluated for physicochemical properties; zone of inhibition, in-vitro diffusion and ex-vivo local accumulation of chloramphenicol. Validation of the design using check-point batch and reduced polynomial equations were also developed. Optimization of the emulsion was developed by software Design® expert 6.0.8. Assessment of the osmolarity, ocular irritation, sterility testing and isotonicity of optimized batch were also made. Results: Parker Neem®, olive and peppermint oils were selected as an oil phase in the ratio 63.64:20.2:16.16. PEG-400 was selected as an emulsifier according to a pseudo-ternary phase diagram. Constrained simplex-centroid design was applied in the range of 25-39% water, 55-69% PEG-400, 5-19% optimized oil mixture, and 1% chloramphenicol. Unpaired Student’s t-test showed for in-vitro and ex-vivo studies that there was a significant difference between the optimized batch of emulsion and Chloramphenicol eye caps (a commercial product) according to both were equally safe. Conclusion: The optimized batch of an emulsion of chloramphenicol was found to be as safe as and more effective than Chloramphenicol eye caps.

scholarly journals In Vitro MCF-7 Cells Apoptosis Analysis of Carboplatin Loaded Silk Fibroin Particles

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1110
Author(s):  
Nanyak Galam ◽  
Pinar Tulay ◽  
Terin Adali
Keyword(s):  
Breast Cancer ◽  
Silk Fibroin ◽  
Drug Carrier ◽  
Release Studies ◽  
Apoptotic Effect ◽  
Student’S T ◽  
Drug Carrier System ◽  
Mcf 7

Breast cancer ranks as the fifth leading cause of death worldwide. Chemotherapy is commonly used directly or as neo-adjuvant therapy for the management of breast cancer with its attendant adverse effects, underscoring the need to develop biocompatible bioactive compounds for pharmacological applications. The aim of this study is to encapsulate carboplatin (CP) with silk fibroin protein (SF) by using an ionic gelation method as a drug carrier system and assess the apoptotic effect on MCF-7 breast cancer cells during in vitro studies. The characterization of silk fibroin encapsulated carboplatin (SFCP) microparticles was analyzed by FTIR spectrophotometer, SEM, Mastersizer, and biodegradation methods. The encapsulation efficiency and release profile of SFCP microparticles were analyzed by an indirect UV–Vis spectrophotometric method. An apoptotic screening of MCF-7 cells was carried out with 10–200 µg/mL CP loaded SFCP, which were cultured for 24, 48, and 72 h. Data were analyzed using the Student’s t test and analysis of variance. FTIR and drug release studies confirmed an interaction of silk fibroin with the carboplatin moiety. SFCP showed successful encapsulation of the carboplatin moiety. Apoptotic screening showed a dose dependent increase in absorbance, indicating significant cell death (p < 0.05). Thus, the direct apoptotic effect of SFCP microparticles on MCF-7 was confirmed.

Erbium: Yttrium-Aluminum-Garnet Laser Application in Stapedotomy

2005 ◽  
Vol 133 (6) ◽  
pp. 923-928 ◽  
Author(s):  
Jacopo Galli ◽  
Claudio Parrilla ◽  
Antonella Fiorita ◽  
Maria Raffaella Marchese ◽  
Gaetano Paludetti
Keyword(s):  
Inner Ear ◽  
Yttrium Aluminum Garnet ◽  
Er:Yag Laser ◽  
Bone Conduction ◽  
Stapes Surgery ◽  
Clinical Safety ◽  
Erbium Laser ◽  
Significant Difference ◽  
Yttrium Aluminum ◽  
Student’S T

OBJECTIVE: To assess clinical safety and efficacy of the erbium: yttrium-aluminum-garnet (Er:YAG) laser in the stapes surgery; to define and optimize parameters that render the procedure safe for the inner ear. STUDY DESIGN: Retrospective study. MATERIAL AND METHODS: A microscope-integrated Er: YAG laser stapedotomy was performed on 29 patients and a conventional stapedotomy on 41 patients. An early (within 1 to 3 days after stapes surgery) and late (at least 6 weeks) pure-tone bone-conduction threshold audiogram was obtained. RESULTS: No statistically significant differences were found by Student's t test over all measured frequencies between pre- and postoperative bone-conduction thresholds in each group. There was no statistically significant difference for all frequencies between early (3 days) and late postoperative mean bone-conduction thresholds. CONCLUSIONS: The results of our preliminary clinical study showed that erbium laser poses no risk to inner ear function. However, the lack of standardization obliges further investigation to establish safe clinical parameters of the Er:YAG laser. EBM RATING: B-3

scholarly journals Effects of Microbubble Size on Ultrasound-Mediated Gene Transfection in Auditory Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ai-Ho Liao ◽  
Yi-Lei Hsieh ◽  
Hsin-Chiao Ho ◽  
Hang-Kang Chen ◽  
Yi-Chun Lin ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Hearing Loss ◽  
Gene Transfer ◽  
Inner Ear ◽  
Hair Cells ◽  
Gene Transfection ◽  
Effective Technique ◽  
Size Dependent ◽  
Genes Encoding

Gene therapy for sensorineural hearing loss has recently been used to insert genes encoding functional proteins to preserve, protect, or even regenerate hair cells in the inner ear. Our previous study demonstrated a microbubble- (MB-)facilitated ultrasound (US) technique for delivering therapeutic medication to the inner ear. The present study investigated whether MB-US techniques help to enhance the efficiency of gene transfection by means of cationic liposomes on HEI-OC1 auditory cells and whether MBs of different sizes affect such efficiency. Our results demonstrated that the size of MBs was proportional to the concentration of albumin or dextrose. At a constant US power density, using 0.66, 1.32, and 2.83 μm albumin-shelled MBs increased the transfection rate as compared to the control by 30.6%, 54.1%, and 84.7%, respectively; likewise, using 1.39, 2.12, and 3.47 μm albumin-dextrose-shelled MBs increased the transfection rates by 15.9%, 34.3%, and 82.7%, respectively. The results indicate that MB-US is an effective technique to facilitate gene transfer on auditory cellsin vitro. Such size-dependent MB oscillation behavior in the presence of US plays a role in enhancing gene transfer, and by manipulating the concentration of albumin or dextrose, MBs of different sizes can be produced.

scholarly journals In vitro study of marginal, internal and proximal adaptation of implant-supported single-crown CAD/CAM restorations

2020 ◽  
Vol 19 ◽  
pp. e207286
Author(s):  
Kamila Aguiar Figueiredo Alves ◽  
Janaina Emanuela Damasceno ◽  
Viviane Maia Barreto de Oliveira ◽  
Luiz Gustavo Cavalcanti Bastos ◽  
Andrea Nóbrega Cavalcanti
Keyword(s):  
Repeated Measures ◽  
T Test ◽  
Digital Impression ◽  
Single Crown ◽  
Significant Difference ◽  
Cad Cam ◽  
Student’S T ◽  
One Way Anova ◽  
Student’S T Test

Aim: This study evaluated the precision of a CAD/CAM system by measuring marginal, internal and proximal fits in implantsupported single-crown restorations. Methods: Ten models of the upper arch were made in which implants replaced the upper left premolars. For fabrication of the zirconia infrastructures, titanium bases (TiBase) were coded and scanned using a scan body. A second digital impression was made for the fabrication of prostheses. Silicone impression material was used to determine the internal clearance between the TiBase and infrastructure and between the infrastructure and crown, whose thickness was measured at three points [P1 (cervical), P2 (middle) and P3 (occlusal)] with a stereoscopic microscope at 70x and 100x magnification. One-way ANOVA for repeated measures and the Student t-test were used for the analysis of internal and marginal adaptation. Proximal contacts were analyzed qualitatively. Results: There was no significant difference between the teeth evaluated (Student’s t-test; p>0.05) or between the corresponding points evaluated in either tooth (one-way ANOVA; p>0.05). Analysis of the internal clearance between the infrastructure and crown demonstrated that all points were significantly different compared to the reference standardized at 100 μm (Student’s t-test p<0.0001). There was no significant difference between P1 and P2, with the thickness at these two points being lower than that obtained at P3 (one-way ANOVA, p<0.05). The proximal contacts did not coincide with the quality defined by the device. Conclusion: The system tested was unable to produce implantsupported single-crown ceramic restorations with marginal, internal and proximal fits matching the digital workflow, with the inferior fits requiring adjustment prior to cementation.

scholarly journals Direct SARS-CoV-2 infection of the human inner ear may underlie COVID-19-associated audiovestibular dysfunction

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Minjin Jeong ◽  
Karen E. Ocwieja ◽  
Dongjun Han ◽  
P. Ashley Wackym ◽  
Yichen Zhang ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hair Cells ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Induced Pluripotent Stem Cell ◽  
In Vitro Models ◽  
Cellular Models ◽  
Induced Pluripotent ◽  
Human Inner Ear

Abstract Background COVID-19 is a pandemic respiratory and vascular disease caused by SARS-CoV-2 virus. There is a growing number of sensory deficits associated with COVID-19 and molecular mechanisms underlying these deficits are incompletely understood. Methods We report a series of ten COVID-19 patients with audiovestibular symptoms such as hearing loss, vestibular dysfunction and tinnitus. To investigate the causal relationship between SARS-CoV-2 and audiovestibular dysfunction, we examine human inner ear tissue, human inner ear in vitro cellular models, and mouse inner ear tissue. Results We demonstrate that adult human inner ear tissue co-expresses the angiotensin-converting enzyme 2 (ACE2) receptor for SARS-CoV-2 virus, and the transmembrane protease serine 2 (TMPRSS2) and FURIN cofactors required for virus entry. Furthermore, hair cells and Schwann cells in explanted human vestibular tissue can be infected by SARS-CoV-2, as demonstrated by confocal microscopy. We establish three human induced pluripotent stem cell (hiPSC)-derived in vitro models of the inner ear for infection: two-dimensional otic prosensory cells (OPCs) and Schwann cell precursors (SCPs), and three-dimensional inner ear organoids. Both OPCs and SCPs express ACE2, TMPRSS2, and FURIN, with lower ACE2 and FURIN expression in SCPs. OPCs are permissive to SARS-CoV-2 infection; lower infection rates exist in isogenic SCPs. The inner ear organoids show that hair cells express ACE2 and are targets for SARS-CoV-2. Conclusions Our results provide mechanistic explanations of audiovestibular dysfunction in COVID-19 patients and introduce hiPSC-derived systems for studying infectious human otologic disease.

135 SHORT-TERM CRYOPRESERVATION OF VITRIFIED MOUSE MORULAE AT - 79°C

2007 ◽  
Vol 19 (1) ◽  
pp. 185
Author(s):  
Y. Takagi ◽  
M. Shimizu ◽  
M. Morimura ◽  
S. Yokomizo ◽  
K. Hara ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Blastocyst Stage ◽  
Control Group ◽  
Embryo Viability ◽  
Chi Square ◽  
Significant Difference ◽  
Morula Stage ◽  
Chi Square Test ◽  
Student’S T

Embryos of various species are successfully vitrified and cryopreserved in liquid nitrogen (&lt;−150°C). Like the preservation of frozen somatic cells cooled by dry ice (−79°C), the cryopreservation of embryos at −79°C is useful for a reduction in the shipping costs. The purpose of this study was to evaluate the effect of the cryopreservation period at −79°C on the in vitro embryo viability of vitrified mouse morulae after thawing. Morula-stage mouse embryos were collected from superovulated ICR donors 70 h after hCG injection. The embryos were exposed first to 5% DMSO + 5% ethylene glycol (EG) in Dulbecco's PBS + 20% FCS (mPBS) for 2 min, and then equilibrated for 20–30 s in a vitrification solution composed of 10% DMSO + 10% EG + 0.6 M sucrose in mPBS. The embryos were loaded onto cryoloops (Lane et al. 1999 Nat. Biotech. 17, 1234–1236) and plunged directly into liquid nitrogen. The cryoloops were placed in 1.2-mL cryotubes and stored in a −79°C freezer for 1–7 days. The embryos were warmed by passing through 4 dilution media and rinsed with mWM culture medium. They were then cultured at 37°C in 5% CO2 for 44 h. Non-cryopreserved embryos and embryos cryopreserved in liquid nitrogen served as controls. Data were analyzed by the chi-square test and the Student's t-test. Results are shown in Table 1. There was no significant difference (P &gt; 0.01) in the developmental abilities to the blastocyst stage of the vitrified embryos that were cryopreserved at −79°C for 1 day, 3 days, and 5 days, the embryos cryopreserved in liquid nitrogen, and the non-vitrified control. The blastocyst rate of embryos was significantly lower (P &lt; 0.01) for the Day 7 group than for the control group. The cell numbers of blastocysts were significantly lower (P &lt; 0.01) for the Day 1, Day 3, Day 5, and Day 7 groups than for the control group. This study suggests that vitrified mouse morulae can be successfully cryopreserved at −79°C for 5 days. Table 1. Effect of the cryopreservation period on the viability of vitrified mouse morulae preserved at −79°C

scholarly journals Phase-locked spiking of inner ear hair cells and the driven noisy Adler equation

2014 ◽  
Vol 4 (6) ◽  
pp. 20140022 ◽  
Author(s):  
Roie Shlomovitz ◽  
Yuttana Roongthumskul ◽  
Seung Ji ◽  
Dolores Bozovic ◽  
Robijn Bruinsma
Keyword(s):  
Inner Ear ◽  
Hair Cells ◽  
Optimal Level ◽  
Sensory Cells ◽  
Experimental Measurements ◽  
Weak Signal ◽  
Sensitive Detector ◽  
Theoretical Predictions ◽  
External Signals

The inner ear constitutes a remarkably sensitive mechanical detector. This detection occurs in a noisy and highly viscous environment, as the sensory cells—the hair cells—are immersed in a fluid-filled compartment and operate at room or higher temperatures. We model the active motility of hair cell bundles of the vestibular system with the Adler equation, which describes the phase degree of freedom of bundle motion. We explore both analytically and numerically the response of the system to external signals, in the presence of white noise. The theoretical model predicts that hair bundles poised in the quiescent regime can exhibit sporadic spikes—sudden excursions in the position of the bundle. In this spiking regime, the system exhibits stochastic resonance, with the spiking rate peaking at an optimal level of noise. Upon the application of a very weak signal, the spikes occur at a preferential phase of the stimulus cycle. We compare the theoretical predictions of our model to experimental measurements obtained in vitro from individual hair cells. Finally, we show that an array of uncoupled hair cells could provide a sensitive detector that encodes the frequency of the applied signal.

scholarly journals Engineered Hypopharynx from Coculture of Epithelial Cells and Fibroblasts Using Poly(ester urethane) as Substratum

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Zhisen Shen ◽  
Jingjing Chen ◽  
Cheng Kang ◽  
Changfeng Gong ◽  
Yabin Zhu
Keyword(s):  
Tissue Engineering ◽  
Epithelial Cells ◽  
Silk Fibroin ◽  
Porous Scaffold ◽  
Engineering Research ◽  
Polymeric Scaffolds ◽  
Cell Tissue ◽  
Silkworm Cocoon

Porous polymeric scaffolds have been much investigated and applied in the field of tissue engineering research. Poly(ester urethane) (PEU) scaffolds, comprising pores of 1–20 μm in diameter on one surface and ≥200 μm on the opposite surface and in bulk, were fabricated using phase separation method for hypopharyngeal tissue engineering. The scaffolds were grafted with silk fibroin (SF) generated from natural silkworm cocoon to enhance the scaffold’s hydrophilicity and further improve cytocompatibility to both primary epithelial cells (ECs) and fibroblasts of human hypopharynx tissue. Coculture of ECs and fibroblasts was conducted on the SF-grafted PEU scaffold (PEU-SF) to evaluate itsin vitrocytocompatibility. After co-culture for 14 days, ECs were lined on the scaffold surface while fibroblasts were distributed in scaffold bulk. The results ofin vivoinvestigation showed that PEU porous scaffold possessed good biocompatibility after it was grafted by silk fibroin. SF grafting improved the cell/tissue infiltration into scaffold bulk. Thus, PEU-SF porous scaffold is expected to be a good candidate to support the hypopharynx regeneration.

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