EKSTRAKSI, PURIFIKASI PARSIAL DAN KARAKTERISASI ALKALIN PROTEASE DARI LIMBAH KULIT BUAH NAGA MERAH

Red dragon fruit is one of famous fruits in Indonesia. High level of red dragon fruit consumption is followed by the high amount of the fruit peel waste. Red dragon fruit peel contains many important compounds, one of them is alkaline protease. Therefore, red dragon fruit peel can be used as an alternative to get an alkaline protease. This research has some purposes, i.e. to characterize the best pH and temperature for the alkaline protease, to determine the most efficient purification process for the protease and to determine the molecular size of alkaline protease. This research began with obtaining the crude extract of alkaline protease from red dragon fruit peel,  followed by pH and temperature characterization, partial purification, i.e. ammonium sulfate precipitation 20%-80%, dialysis and Ion Exchange Chromatography using Biorex Cation Exchange Resins, and finally SDS PAGE. The result showed that the optimum temperature for alkaline protease activity was 60°C and the optimum pH for alkaline protease activity was 8. In the final step of purification, namely ion exchange chromatography (IEC), the specific activity value was 6,2 x 10-4 µmol/µg.min, indicating a 3,29 fold purification of the initial crude extract. In this research, the alkaline protease showed a  molecular mass of 23 kDa

Recent Advances in Electrochemical Sensors for the Detection of Biomolecules and Whole Cells

Electrochemical sensors are considered an auspicious tool to detect biomolecules (e.g., DNA, proteins, and lipids), which are valuable sources for the early diagnosis of diseases and disorders. Advances in electrochemical sensing platforms have enabled the development of a new type of biosensor, enabling label-free, non-destructive detection of viability, function, and the genetic signature of whole cells. Numerous studies have attempted to enhance both the sensitivity and selectivity of electrochemical sensors, which are the most critical parameters for assessing sensor performance. Various nanomaterials, including metal nanoparticles, carbon nanotubes, graphene and its derivatives, and metal oxide nanoparticles, have been used to improve the electrical conductivity and electrocatalytic properties of working electrodes, increasing sensor sensitivity. Further modifications have been implemented to advance sensor platform selectivity and biocompatibility using biomaterials such as antibodies, aptamers, extracellular matrix (ECM) proteins, and peptide composites. This paper summarizes recent electrochemical sensors designed to detect target biomolecules and animal cells (cancer cells and stem cells). We hope that this review will inspire researchers to increase their efforts to accelerate biosensor progress—enabling a prosperous future in regenerative medicine and the biomedical industry

Recent advances and challenges in organoid-on-a-chip technology

Conventional 2-dimensional cell culture poorly mimics human-relevant models, which is considered a major challenge in biological research. Organoids are a recent breakthrough in 3-dimensional (3D) in vitro tissue engineering that better reflect the physiological, morphological, and functional properties of in vivo organs (e.g., brain, heart, kidney, lung, and liver). Consequently, organoids are extensively used in various impactful biomedical applications including organ development, disease modeling, and clinical drug testing. However, organoid technology still has several limitations, including low reproducibility, vascularization, limited nutrient uptake and distribution (affecting the level of organoid maturation), lack of standardization, and intra-clonal variability. Efforts have been made to overcome these shortcomings of organoid culture. Microfluidic technology has successfully facilitated the establishment of organoid-on-a-chip systems, which effectively improve the structural and physiological features of organoids in a controlled manner. This review discusses the recent advances and developments in organoid-on-a-chip technology. We hope that this study will motivate researchers to explore the possible engagement between microfluidic devices and self-assembled 3D cell cultures to leverage the enhanced quality of organoids, which will have favorable impacts on future tissue regeneration and regenerative therapies

Two-dimensional material-based bionano platforms to control mesenchymal stem cell differentiation

Abstract Background In the past decade, stem cells, with their ability to differentiate into various types of cells, have been proven to be resourceful in regenerative medicine and tissue engineering. Despite the ability to repair damaged parts of organs and tissues, the use of stem cells still entails several limitations, such as low differentiation efficiency and difficulties in guiding differentiation. To address these limitations, nanotechnology approaches have been recently implemented in stem cell research. It has been discovered that stem cells, in combination with carbon-based functional materials, show enhanced regenerative performances in varying biophysical conditions. In particular, several studies have reported solutions to the conventional quandaries in biomedical engineering, using synergetic effects of nanohybrid materials, as well as further development of technologies to recover from diverse health conditions such as bone fracture and strokes. Main text In this review, we discuss several prior studies regarding the application of various nanomaterials in controlling the behavior of stem cells. We focus on the potential of different types of nanomaterials, such as two-dimensional materials, gold nanoparticles, and three-dimensional nanohybrid composites, to control the differentiation of human mesenchymal stem cells (hMSCs). These materials have been found to affect stem cell functions via the adsorption of growth/differentiation factors on the surfaces of nanomaterials and the activation of signaling pathways that are mostly related to cell adhesion and differentiation (e.g., FAK, Smad, Erk, and Wnt). Conclusion Controlling stem cell differentiation using biophysical factors, especially the use of nanohybrid materials to functionalize underlying substrates wherein the cells attach and grow, is a promising strategy to achieve cells of interest in a highly efficient manner. We hope that this review will facilitate the use of other types of newly discovered and/or synthesized nanomaterials (e.g., metal transition dichalcogenides, non-toxic quantum dots, and metal oxide frameworks) for stem cell-based regenerative therapies

Nanobiosensing Platforms for Real-Time and Non-Invasive Monitoring of Stem Cell Pluripotency and Differentiation

Breakthroughs in the biomedical and regenerative therapy fields have led to the influential ability of stem cells to differentiate into specific types of cells that enable the replacement of injured tissues/organs in the human body. Non-destructive identification of stem cell differentiation is highly necessary to avoid losses of differentiated cells, because most of the techniques generally used as confirmation tools for the successful differentiation of stem cells can result in valuable cells becoming irrecoverable. Regarding this issue, recent studies reported that both Raman spectroscopy and electrochemical sensing possess excellent characteristics for monitoring the behavior of stem cells, including differentiation. In this review, we focus on numerous studies that have investigated the detection of stem cell pluripotency and differentiation in non-invasive and non-destructive manner, mainly by using the Raman and electrochemical methods. Through this review, we present information that could provide scientific or technical motivation to employ or further develop these two techniques for stem cell research and its application