[Intraocular Pressure Sensor Based on a Contact Lens].

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.

The Circadian System Contributes to Apnea Lengthening across the Night in Obstructive Sleep Apnea.

STUDY OBJECTIVE: To test the hypothesis that respiratory event duration exhibits an endogenous circadian rhythm. DESIGN: Within-subject and between-subjects. SETTINGS: Inpatient intensive physiologic monitoring unit at the Brigham and Women's Hospital. PARTICIPANTS: Seven subjects with moderate/severe sleep apnea and four controls, age 48 (SD = 12) years, 7 males. INTERVENTIONS: Subjects completed a 5-day inpatient protocol in dim light. Polysomnography was recorded during an initial control 8-h night scheduled at the usual sleep time, then through 10 recurrent cycles of 2 h 40 min sleep and 2 h 40 min wake evenly distributed across all circadian phases, and finally during another 8-h control sleep period. MEASUREMENTS AND RESULTS: Event durations, desaturations, and apnea-hypopnea index for each sleep opportunity were assessed according to circadian phase (derived from salivary melatonin), time into sleep, and sleep stage. Average respiratory event durations in NREM sleep significantly lengthened across both control nights (21.9 to 28.2 sec and 23.7 to 30.2 sec, respectively). During the circadian protocol, event duration in NREM increased across the circadian phases that corresponded to the usual sleep period, accounting for > 50% of the increase across normal 8-h control nights. AHI and desaturations were also rhythmic: AHI was highest in the biological day while desaturations were greatest in the biological night. CONCLUSIONS: The endogenous circadian system plays an important role in the prolongation of respiratory events across the night, and might provide a novel therapeutic target for modulating sleep apnea.

A silica-polymer composite nano system for tumor-targeted imaging and p53 gene therapy of lung cancer.

In our study, a silica-polymer composite nano system (MB-NSi-p53-CS ternary complexes) composed of methylene blue-encapsulated amine-terminated silica nanoparticles (MB-NSi) and chondroitin sulfate (CS) were successfully developed for tumor-targeted imaging and p53 gene therapy of lung cancer. MB was employed as a NIR probe for in vivo imaging, MB-NSi nanoparticles were served as gene vector, while CS was applied to be a coating and targeting polymer. MB-NSi-p53-CS ternary complexes displayed nanosized diameter, effective p53 condensation ability, efficient p53 protection profile, and superior bovine serum albumin stability in vitro. Experiments on A549 cell line further revealed low cytotoxicity, high p53 transfection, and anticancer efficacy of MB-NSi-p53-CS ternary complexes. In vivo imaging and tumor targetability assays demonstrated that MB-NSi-p53-CS ternary complexes were a preferable system with desirable imaging and tumor-targeting properties.

Effects of subretinal implant materials on the viability, apoptosis and barrier function of cultured RPE cells.

BACKGROUND: Subretinal microphotodiode array (MPDA) is a type of visual prosthesis used for the implantation in the subretinal space of patients with progressive photoreceptor cell loss. The present study aimed to evaluate the effect of materials for MPDA on the viability, apoptosis and barrier function of cultured pig retinal pigment epithelium (RPE) cells. METHODS: Primary culture of pig RPE cells was performed and 24 pig eyes were used to start RPE culture. The third passage of the cultures was plated on different materials for MPDA and MPDAs. The tetrazolium dye-reduction assay (MTT) was used to determine RPE cell viability. Flow cytometry was measured to indicate the apoptosis rates of RPE cells on different materials. RPE cells were also cultured on microporous filters, and the transepithelial resistance and permeability of the experimental molecule were measured to determine the barrier function. RESULTS: The data from all the methods indicated no significant difference between the materials groups and the control group, and the materials tested showed good biocompatibility. CONCLUSIONS: The materials for MPDA used in the present study had no direct toxicity to the RPE cells and did not release harmful soluble factors that affected the barrier function of RPE in vitro.