Recent Progress in Azobenzene-Based Supramolecular Materials and Applications.

Azobenzene-containing small molecules and polymers are functional photoswitchable molecules to form supramolecular nanomaterials for various applications. Recently, supramolecular nanomaterials have received enormous attention in material science because of their simple bottom-up synthesis approach, understandable mechanisms and structural features, and batch-to-batch reproducibility. Azobenzene is a light-responsive functional moiety in the molecular design of small molecules and polymers and is used to switch the photophysical properties of supramolecular nanomaterials. Herein, we review the latest literature on supramolecular nano- and micro-materials formed from azobenzene-containing small molecules and polymers through the combinatorial effect of weak molecular interactions. Different classes including complex coacervates, host-guest systems, co-assembled, and self-assembled supramolecular materials, where azobenzene is an essential moiety in small molecules, and photophysical properties are discussed. Afterward, azobenzene-containing polymers-based supramolecular photoresponsive materials formed through the host-guest approach, polymerization-induced self-assembly, and post-polymerization assembly techniques are highlighted. In addition to this, the applications of photoswitchable supramolecular materials in pH sensing, and CO2 capture are presented. In the end, the conclusion and future perspective of azobenzene-based supramolecular materials for molecular assembly design, and applications are given.

Silver-incorporating peptide and protein supramolecular nanomaterials for biomedical applications.

The natural biomolecules of peptides and proteins are able to form elegant metal incorporating supramolecular nanomaterials through multiple weak non-covalent interactions. The use of toxic chemical reagents to fabricate silver nanoparticles poses a danger to apply them in various biomedical applications. Peptide and protein biomolecules have the potential to overcome this barrier by the supramolecular chemistry approach. In this review, we focus on the self-assembly of peptides and proteins to synthesize silver incorporating supramolecular nanoarchitectures, which in turn enhance the biological properties of these silver nanomaterials being used in nanomedicine. This review aims to illustrate the recent developments in amphiphilic peptides, oligopeptides, collagen, bovine serum albumin (BSA), and human serum albumin (HSA) as capping, stabilizing, and reducing agents to form silver incorporating supramolecular nanostructures. Finally, we provide some biomedical applications of silver-incorporating supramolecular nanomaterials along with future perspectives.

Hemoglobin structure at higher levels of hemoglobin A1C in type 2 diabetes and associated complications.

BACKGROUND: Fourier transform infrared (FTIR) spectroscopy technique has not been used as a diagnostic tool for diabetes in clinical practice. This study was linked to structural changes in hemoglobin (Hb) in type 2 diabetes patients at higher levels of HbA1C using FTIR spectroscopy. METHODS: Fifty-three diabetic patients from the Bahawal Victoria Hospital, Bahawalpur, Pakistan were categorized as group A (6% < HbA1C < 7%; n = 25) and group B (HbA1C ≥9%; n = 28). Another group (group N) of twenty blood samples was taken from healthy people from the Islamia University Bahawalpur, Pakistan. Data from all groups were collected from January 1, 2018 to March 31, 2019. The structure of Hb was studied by FTIR spectroscopy and impact of glucose on the fine structure of HbA1C was estimated. RESULTS: Hb secondary structure erythrocyte parameters were altered by changing glucose concentrations. From FTIR spectra of all three groups it was found that Hb structure was slightly altered in group A, but significantly changed in group B (P < 0.05). There was an increase in ß-sheet structure and a reduction in α-helix structure at elevated levels of HbA1C (group B) in type 2 diabetes. CONCLUSION: We suggest that higher level of glycation reflected by increased HbA1C might be a contributing factor to structural changes in Hb in type 2 diabetic patients. FTIR spectroscopy can be a novel technique to find pathogenesis in type 2 diabetes.

Attenuated total reflectance spectroscopy to diagnose skin cancer and to distinguish different metastatic potential of melanoma cell.

Early diagnosing of skin cancer and investigation of metastatic potential of cancer cells are very important to treat it appropriately. Infrared spectroscopy of biological tissues is an emerging technique which gives the spectral differences between healthy and diseased cells. In this work, we have demonstrated that attenuated total reflectance Fourier transform (ATR-FTIR) spectroscopy can be used in diagnostic of skin cancer and in differentiating metastatic potential of cancer cells. Using IR spectroscopy, we can identify various types of cancer such as basal cell carcinoma, malignant melanoma, nevus and metastatic potential by alternations in hydration level and molecular changes. We examined biopsy of different types of cancer cells to diagnose skin cancer at early stages by using FTIR spectroscopy. To differentiate metastases we examined two human melanoma cells of same patient but at different metastatic potential and two murine melanoma cells with common genetic background but different metastatic potential. Our findings revealed that melanoma changes the permeability of cell membrane and higher metastatic potential is related to the hydration level of cell membrane. Thus, ATR-FTIR spectroscopy is a potential technique to help in early diagnosing of skin cancer and to differentiate different metastatic potentials.

A comparative study of RapidArc and intensity-modulated radiotherapy plan quality for cervical cancer treatment.

BACKGROUND: RapidArc therapy, a complex form of intensity-modulated radiotherapy (IMRT), is now widely used to treat cancer patients. AIMS: This study aimed to investigate and compare the plan quality of IMRT and RapidArc techniques using various dosimetric indices to find the better treatment modality for treating patients with cervix cancer. MATERIALS AND METHODS: Thirteen cervical cancer patients treated with IMRT were selected for analysis and original plans were subsequently re-optimized using the RapidArc technique. Plans were generated such that dose of 5000 cGy was delivered in 25 equal fractions. Inverse planning was done by Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system for 15 MV photon beams from computed tomographic data. Double arcs were used for RapidArc plans. Quality of treatment plans was evaluated by calculating conformity index (CI), homogeneity index (HI), gradient index (GI), coverage, and unified dosimetry index (UDI) for each plan. RESULTS AND CONCLUSION: RapidArc resulted in better planning target volume (PTV) coverage as is evident from its superior conformation number, coverage, CI, HI, GI, and UDI. Regarding organs at risk (OARs), RapidArc plans exhibit superior organ sparing as is evident from integral dose comparison. Difference between both techniques was determined by statistical analysis. For all cases under study, modest differences between IMRT and RapidArc treatment were observed. RapidArc-based treatment planning is safer with similar planning goals compared to the standard fixed IMRT technique. This study clearly demonstrated that favorable dose distribution in PTV and OARs was achieved using RapidArc technique, and hence, the risk of damage to normal tissues is reduced.