Carbon dot-based biosensors for the detection of communicable and non -communicable diseases.

Due to their fascinating chemical, optical, electrical, and biological properties carbon dots (CDs or CDots), carbon quantum dots (CQDs), and graphene quantum dots (GQDs) have attracted attention in biosensing as they can greatly improve the detection limit, sensitivity, and selectivity of biosensors. In general, CDs, CQDs, and GQDs are a class of carbon-based nanomaterials that are characterized by extraordinary fluorescence, a size less than 10 nm, high stability, low toxicity, and being easy to synthesize and presenting functional groups in their surface area that vary according to their synthesis source. In this review, a general description of the main methods and precursors reported in the scientific literature for the synthesis of CDs, CQDs, and GQDs are presented, as well as the chemical, optical, electrical, and biological properties that stand out the most from them; moreover, the main objective of this review is to summarize the application of these carbonaceous nanomaterials in biosensors for the detection of communicable and non-communicable diseases. The article summarizes the applications of CDs, CQDs, and GQDs according to the group of diseases they detected using the international classification of diseases in its 10th edition (ICD-10). To facilitate the reader's access to significant information from these biosensors, several tables summarize the information associated with the type of biomarker, the working ranges, and the biosensor assembly.

Formulation and Characterization of a New Injectable Bone Substitute Composed PVA/Borax/CaCO3 and Demineralized Bone Matrix.

The occurrence of bone-related disorders and diseases has dramatically increased in recent years around the world. Demineralized bone matrix (DBM) has been widely used as a bone implant due to its osteoinduction and bioactivity. However, the use of DBM is limited because it is a particulate material, which makes it difficult to manipulate and implant with precision. In addition, these particles are susceptible to migration to other sites. To address this situation, DBM is commonly incorporated into a variety of carriers. An injectable scaffold has advantages over bone grafts or preformed scaffolds, such as the ability to flow and fill a bone defect. The aim of this research was to develop a DBM carrier with such viscoelastic properties in order to obtain an injectable bone substitute (IBS). The developed DBM carrier consisted of a PVA/glycerol network cross-linked with borax and reinforced with CaCO3 as a pH neutralizer, porosity generator, and source of Ca. The physicochemical properties were determined by an injectability test, FTIR, SEM, and TGA. Porosity, degradation, bioactivity, possible cytotoxic effect, and proliferation in osteoblasts were also determined. The results showed that the developed material has great potential to be used in bone tissue regeneration.