Diabetes is a global endemic with rapidly increasing prevalence in both developing and developed countries. The American Diabetes Association has recommended glycated hemoglobin (HbA1c) as a possible substitute to fasting blood glucose for diagnosis of diabetes. HbA1c is an important indicator of long-term glycemic control with the ability to reflect the cumulative glycemic history of the preceding two to three months. HbA1c not only provides a reliable measure of chronic hyperglycemia but also correlates well with the risk of long-term diabetes complications. Elevated HbA1c has also been regarded as an independent risk factor for coronary heart disease and stroke in subjects with or without diabetes. The valuable information provided by a single HbA1c test has rendered it as a reliable biomarker for the diagnosis and prognosis of diabetes. This review highlights the role of HbA1c in diagnosis and prognosis of diabetes patients.

Impaired lipid metabolism resulting from uncontrolled hyperglycaemia has been implicated in cardiovascular complications in diabetes patients. The aim of this study was to examine the impact of glycaemic control on the lipid profile of diabetic patients. We also determined the ability of glycated haemoglobin (HbA(1c)) as an indirect marker of dyslipidaemia. A total of 1011 type 2 diabetic patients (males, 574; females, 437; mean age, 59.76 years) were included in this study. Venous blood samples were collected from all the subjects after at least 8 h fasting. The sera were analysed for HbA(1c), fasting blood glucose (FBG), total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL). The levels of HbA(1c), FBG and LDL did not differ significantly between males and females. Female patients showed significantly higher serum cholesterol and HDL but significantly lower TG levels as compared to males. There was a highly significant correlation between HbA(1c) and FBG. Both HbA(1c) and FBG exhibited direct correlations with cholesterol, TG and LDL and inverse correlation with HDL; the magnitude of significance for all these lipid parameters being greater with HbA(1c) than FBG. There was a linear relationship between HbA(1c) and dyslipidaemia. The levels of serum cholesterol and TG were significantly higher and of HDL significantly lower in patients with worse glycaemic control as compared to patients with good glycaemic control. The findings of this study clearly indicate that HbA(1c) is not only a useful biomarker of long-term glycaemic control but also a good predictor of lipid profile. Thus, monitoring of glycaemic control using HbA(1c) could have additional benefits of identifying diabetic patients who are at a greater risk of cardiovascular complications.

This review article summarizes the latest progress in research regarding bioapplications of graphene oxide derivatives and provides expert opinions on strategies for overcoming the current challenges.

The combined delivery of photo- and chemo-therapeutic agents is an emerging strategy to overcome drug resistance in treating cancer, and controlled light-responsive drug release is a proven tactic to produce a continuous therapeutic effect for a prolonged duration. Here, a combination of light-responsive graphene, chemo-agent doxorubicin and pH-sensitive disulfide-bond linked hyaluronic acid form a nanogel (called a graphene-doxorubicin conjugate in a hyaluronic acid nanogel) that exerts an activity with multiple effects: thermo and chemotherapeutic, real-time noninvasive imaging, and light-glutathione-responsive controlled drug release. The nanogel is mono-dispersed with an average diameter of 120 nm as observed by using TEM and a hydrodynamic size analyzer. It has excellent photo-luminescence properties and good stability in buffer and serum solutions. Graphene itself, being photoluminescent, can be considered an optical imaging contrast agent as well as a heat source when excited by laser irradiation. Thus the nanogel shows simultaneous thermo-chemotherapeutic effects on noninvasive optical imaging. We have also found that irradiation enhances the release of doxorubicin in a controlled manner. This release synergizes therapeutic activity of the nanogel in killing tumor cells. Our findings demonstrate that the graphene-doxorubicin conjugate in the hyaluronic acid nanogel is very effective in killing the human lung cancer cell line (A549) with limited toxicity in the non-cancerous cell line (MDCK).

Gold nanoparticles (GNPs) are biocompatible nanomaterials that are currently researched for biomedical applications such as imaging and targeted drug delivery. In this investigation, we studied the effects of a single dose (injected on day 1) as well as a priming dose (two injections with a gap of one week) of 5 nm, 20 nm, and 50 nm diameter GNPs on the structural and biochemical changes in the liver, kidney, and spleen of mice. The results showed that small sized GNPs (5 nm) produced significant pathological changes in the liver on day 2 that gradually reduced on day 8. The medium (20 nm) and large (50 nm) sized GNPs preferentially targeted the spleen and caused significant pathological changes to the spleen architecture on day 2 that persisted on day 8 as well. There were minimal and insignificant pathological changes to the kidneys irrespective of the GNPs size. The animals that were primed with the pre-exposure of GNPs did not show any aggravation of histological changes after the second dose of the same GNPs. None of the dose regimens of the GNPs were able to significantly affect the markers of oxidative stress including glutathione (GSH) and malondialdehyde (MDA) in all of the organs that were studied. In conclusion, the size of GNPs plays an important role in their pathological effects on different organs of mice. Moreover, the primed animals become refractory to further pathological changes after the second dose of GNPs, suggesting the importance of a priming dose in medical applications of GNPs.