Among homopolypeptides, polyproline is unique due to its conformational flexibility between right-handed PPI and left-handed PPII helices. Herein, we designed a propargyloxy-functionalized proline-NCA monomer, so that the ring-opening polymerization (ROP) of the former provides a reactive propargyl group in each repeating unit to enable postpolymerization modifications. A close match between the feed ratio and degree of polymerization estimated using 1 H NMR along with a low dispersity (Đ) suggests that the ROP was executed in a controlled manner. We then used azide-yne click chemistry to prepare polyproline chains that had been triethyleneoxy (TEG)-functionalized (periodically grafted). Later, functionalized polyprolines were compared with native polyprolines in terms of thermoresponsive behavior using turbidimetric analysis, circular dichroism (CD), and variable temperature NMR (VT NMR) spectroscopy. Despite sharing similar polyproline backbones, these two polymers differ significantly in their thermoresponsive behavior. VT NMR and CD studies revealed that water-soluble TEG residues in combination with enhanced conformational stability of the functionalized polyproline could be the reason behind the different thermoresponsiveness between these two polymers.

Though “Foldamers” have greatly developed, molecules that fold beyond 2o structures are less common. We present the design and synthesis of triblock copolymers of the “A‐B‐A” type containing two types of helix formation blocks. Two blocks (A & B) were chosen, with one comprised of L‐polyproline as block “A” and the other block (B) comprised with three Naphthalene diimide (NDI)‐derivatives separated by two proline residues. Block (B) has been carefully designed to serve as a bifunctional initiator for the ring‐opening polymerization (ROP) of proline‐N‐carboxy anhydride as well as to encapsulate an electron‐rich aromatic species by charge transfer complexation (C‐T). As a result of (C‐T) complexation with dialkoxy pyrene, the native helical structure of the middle block was transformed into a 1D columnar structure without affecting the 2o structure of the polyproline block. In this way, the initial helix1‐b‐helix2‐b‐helix1 structure of the block copolymers was transformed into a helix1‐b‐columnar‐b‐helix1 structure. The C‐T complexation and related structural changes of the block copolymers were characterized using UV‐Vis, Fluorescence and Circular dichroism (CD) spectroscopy.This article is protected by copyright. All rights reserved

Objectives: Infections of sterile body fluids are important and significant causes of mortality and morbidity, especially healthcare-associated infections. Species-level identification and antimicrobial resistance profile of bacteria are important determinants while selecting appropriate antimicrobials for empirical and targeted therapy. We conducted this study to observe the distribution of various bacteria and their antimicrobial resistance profile isolated from sterile body fluids. Materials and Methods: We conducted this study in a tertiary care teaching hospital from western Uttar Pradesh for a period of 2 years. All sterile body fluid samples were processed by conventional aerobic bacterial culture followed by their identification up to species level by conventional biochemicals following standard microbiological procedures. The antimicrobial susceptibility of the bacterial pathogens grown in culture was tested by Kirby–Bauer disk diffusion method and interpretation of susceptibility testing was done according to CLSI guidelines 2020. Results: A total of 1980 sterile body fluid samples were collected during the study period and 192 samples were found positive on culture for bacterial pathogens. Gram-negative bacilli (GNB) were predominantly isolated comprising 83.33% in comparison to 16.67 % of Gram-positive cocci. Among Staphylococcus aureus isolates, 75% were methicillin-resistant S. aureus. All S. aureus isolates were sensitive against vancomycin and linezolid. Among GNB, 25% were extended-spectrum beta-lactamase producers while 62.5% were carbapenemase producers. All GNBs were sensitive to colistin. Conclusion: From this study, we concluded that the pathogenic bacteria implicated in infections of sterile body fluids are predominantly multidrug-resistant. There is a huge variation in data on the distribution of bacterial species isolated from sterile body fluids and their antimicrobial resistance patterns from different geographical locations and healthcare settings. Thus, data from a particular healthcare setting are important for empirical treatment in that healthcare setting.

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