A microfluidic in-line ELISA for measuring secreted protein under perfusion.

Recent progress in the development of microfluidic microphysiological systems such as 'organs-on-chips' and microfabricated cell culture is geared to simulate organ-level physiology. These tissue models leverage microengineering technologies that provide capabilities of presenting cultured cells with input signals in a more physiologically relevant context such as perfused flow. Proteins that are secreted from cells have important information about the health of the cells. Techniques to quantify cellular proteins include mass spectrometry to ELISA (enzyme-linked immunosorbent assay). Although our capability to perturb the cells in the microphysiological systems with varying inputs is well established, we lack the tools to monitor in-line the cellular responses. User intervention for sample collection and off-site is cumbersome, causes delays in obtaining results, and is especially expensive because of collection, storage, and offline processing of the samples, and in many case, technically impractical to carry out because of limitated sample volumes. To address these shortcomings, we report the development of an ELISA that is carried out in-line under perfusion within a microfluidic device. Using this assay, we measured the albumin secreted from perfused hepatocytes without and under stimulation by IL-6. Since the method is based on a sandwich ELISA, we envision broad application of this technology to not just organs-on-chips but also to characterizing the temporal release and measurement of soluble factors and response to drugs.

Factors related to perceived needs of primary caregivers of patients with schizophrenia.

BACKGROUND/PURPOSE: Schizophrenia is a chronic mental illness, and sufferers are usually dependent on family, primary caregivers in particular. The present study was designed to assess the perceived needs of caregivers so that adequate services can be provided for them in the community. METHODS: A total of 177 primary caregivers were interviewed with the structured burden-and-need schedules to determine their perceived needs, and the related clinical and demographic factors. Fourteen perceived needs were identified and classified into different need clusters using the generalized association plots. A multiple regression of logistic model was adopted to explore the relationships between the related factors and perceived needs. RESULTS: Four clusters of perceived needs were identified, which included assistant patient care (77.6%), access to relevant information (66.1%), societal support (68.2%), and burden release (27.2%). These needs were significantly related to number of admissions, duration of illness, relationship between caregiver and patient, and education level of the caregiver. CONCLUSION: Four clusters of caregivers' perceived needs were identified and found to be related to psychopathologic and demographic factors. These data are of value in designing appropriate community psychiatric programs to improve the quality of care and enhance the capacity of primary caregivers to care for patients.