Applications of Gelatin in Biosensors: Recent Trends and Progress

Recent advances of bioaerogels in medicine: Preparation, property and application

Bioaerogels represent a type of three-dimensional porous materials fabricated from natural biopolymers, and show a significant potential for medical application due to their characteristics of extremely low density, high specific surface area, excellent biocompatibility and biodegradability. The preparation method and parameters of bioaerogels are focused on, and their influence on the structure and properties of bioaerogels are discussed in detail. Then, to match the properties of bioaerogels with the medical applications, this work emphasizes the main properties (including biocompatibility, degradability, and mechanical properties), structural parameters (such as suitable porosity, pore size and high specific surface area), and further summarizes the influence of single-component and composite bioaerogels on their properties. Moreover, according to the different applications (wound healing, drug delivery, and tissue engineering and other fields), the function method, mechanism and practical effect of bioaerogels are comprehensively analyzed. Finally, the challenges, future research directions, and solutions for the practical application of bioaerogels in medicine are discussed.

Accurate, affordable, and easy electrochemical detection of ascorbic acid in fresh fruit juices and pharmaceutical samples using an electroactive gelatin sulfonamide

In this study, we demonstrated how to design and construct a highly specific and sensitive sensor capable of rapidly and accurately detecting ascorbic acid (AA). A sulfonamide derivative (S) acting as a novel monomer was synthesized through an aldol condensation reaction. Subsequently, a free radical-mediated grafting polymerization approach was used to create a new generation of gelatin (Gel) grafted with poly sulfonamide derivative (Gel-g-PS). The graft percentage (GP%) was 60 ± 0.5% with a conversion rate of 98.3%. Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were utilized to confirm the formation of Gel-g-PS. The developed gelatin sulfonamide modified screen printed electrode (Gel-g-PS/SPE) was employed for the determination of ascorbic acid (AA) in fruit juices and pharmaceutical samples. Gel-g-PS/SPE showed excellent electrochemical catalytic activities toward AA oxidation compared to bare (unmodified) SPE. Ascorbic acid displayed a sensitive oxidation peak at 0.35 V using the differential pulse voltammetry technique. Under optimized experimental conditions, the two linear ranges for AA detection were obtained to be from 0.2-5 ppb and 20-600 ppb, with a limit of detection (LoD) of 0.03 ppb and a limit of quantification (LoQ) of 0.11 ppb. The proposed Gel-g-PS modified SPE surface demonstrated good selectivity, stability, reproducibility, and repeatability as well as a good recovery rate in fresh fruit juices and pharmaceutical samples.

Regeneration and Long-Term Stability of a Low-Power Eco-Friendly Temperature Sensor Based on a Hydrogel Nanocomposite

A water-processable and low-cost nanocomposite material, based on gelatin and graphene, has been used to fabricate an environmentally friendly temperature sensor. Demonstrating a temperature-dependent open-circuit voltage between 260 and 310 K, the sensor effectively detects subzero ice formation. Notably, it maintains a constant temperature sensitivity of approximately -19 mV/K over two years, showcasing long-term stability. Experimental evidence demonstrates the efficient regeneration of aged sensors by injecting a few drops of water at a temperature higher than the gelation point of the hydrogel nanocomposite. The real-time monitoring of the electrical characteristics during the hydration reveals the initiation of the regeneration process at the gelation point (~306 K), resulting in a more conductive nanocomposite. These findings, together with a fast response and low power consumption in the range of microwatts, underscore the potential of the eco-friendly sensor for diverse practical applications in temperature monitoring and environmental sensing. Furthermore, the successful regeneration process significantly enhances its sustainability and reusability, making a valuable contribution to environmentally conscious technologies.

Enzymes Immobilized into Starch- and Gelatin-Based Hydrogels: Properties and Application in Inhibition Assay

The present work is a review of the research on using hydrogels based on natural biodegradable polymers, starch, and gelatin for enzyme immobilization. This review addresses the main properties of starch and gelatin that make them promising materials in biotechnology for producing enzyme preparations stable during use and storage and insensitive to chemical and physical impacts. The authors summarize their achievements in developing the preparations of enzymes immobilized in starch and gelatin gels and assess their activity, stability, and sensitivity for use as biorecognition elements of enzyme inhibition-based biosensors.

Effect of Flow Velocity on Laminar Flow in Microfluidic Chips

Gel fibers prepared based on microfluidic laminar flow technology have important research value in constructing biomimetic scaffolds and tissue engineering. The key point of microfluidic laminar flow technology is to find the appropriate fluid flow rate in the micropipe. In order to explore the influence of flow rate on the laminar flow phenomenon of a microfluidic chip, a microfluidic chip composed of an intermediate main pipe and three surrounding outer pipes are designed, and the chip is prepared by photolithography and the composite molding method. Then, a syringe pump is used to inject different fluids into the microtubing, and the data of fluid motion are obtained through fluid dynamics simulation and finite element analysis. Finally, a series of optimal adjustments are made for different fluid composition and flow rate combinations to achieve the fluid's stable laminar flow state. It was determined that when the concentration of sodium alginate in the outer phase was 1 wt% and the concentration of CaCl₂ in the inner phase was 0.1 wt%, the gel fiber prepared was in good shape, the flow rate was the most stable, and laminar flow was the most obvious when the flow rate of both was 1 mL/h. This study represents a preliminary achievement in exploring the laminar flow rate and fabricating gel fibers, thus offering significant reference value for investigating microfluidic laminar flow technology.

Biosensors in 2022

Sixty years have passed since Clark and Lyons proposed the concept of using glucose enzyme electrodes to monitor the oxygen that is consumed during an enzyme-catalyzed reaction [...].

Gelatin Matrix as Functional Biomaterial for Immobilization of Nanoparticles of Metal-Containing Compounds

The data concerning the synthesis and physicochemical characteristics of specific functional biomaterials-biopolymer-immobilized matrix systems based on gelatin as an array and chemical compounds, which include atoms of various metal elements-are systematized and discussed. The features of this biopolymer which determine the specific properties of the immobilized matrix systems formed by it and their reactivity, are noted. Data on gelatin-immobilized systems in which immobilized substances are elemental metals and coordination compounds formed as a result of redox processes, nucleophilic/electrophilic substitution reactions, and self-assembly (template synthesis), are presented. The possibilities of the practical use of metal-containing gelatin-immobilized systems are promising for the future; in particular, their potential in medicine and pharmacology as a vehicle for "targeted" drug delivery to various internal organs/tissues of the body, and, also, as potential biosensors is noted.

Gelatin and Chitosan as Meat By-Products and Their Recent Applications

Meat by-products such as bones, skin, horns, hooves, feet, skull, etc., are produced from slaughtered mammals. Innovative solutions are very important to achieving sustainability and obtaining the added value of meat by-products with the least impact on the environment. Gelatin, which is obtained from products high in collagen, such as dried skin and bones, is used in food processing, and pharmaceuticals. Chitosan is derived from chitin and is well recognized as an edible polymer. It is a natural product that is non-toxic and environmentally friendly. Recently, chitosan has attracted researchers' interests due to its biological activities, including antimicrobial, antitumor, and antioxidant properties. In this review, article, we highlighted the recent available information on the application of gelatin and chitosan as antioxidants, antimicrobials, food edible coating, enzyme immobilization, biologically active compound encapsulation, water treatment, and cancer diagnosis.