Antibacterial and safe chitosan-graphene hydrogel films: a promising nanotherapeutic for wound infections.

Pathogenic bacterial growth at wound sites, particularly , poses a serious threat during trauma. Delayed treatment can lead to increased inflammation and severe tissue damage. In this study, a chitosan cross-linked polycationic peptide-conjugated graphene-silver (CGrAP) nanocomposite hydrogel film was developed as an antibacterial wound dressing to treat infections.

Boosting Supramolecular Gelation Efficiency and Properties: Ionic Strength as a Key to Superior Hydrogels.

Controlling the minimum gelation concentration (MGC) of low molecular weight (LMW) hydrogelators is a key for modulating gel properties, such as mechanical strength, viscoelasticity, and stability, which are crucial for applications ranging from drug delivery to tissue engineering. However, tweaking the MGC under specific conditions, such as pH and/or temperature, poses a considerable challenge. Herein, we varied the ionic strength of buffer solutions using NaCl for several LMW hydrogelators, including Fmoc-Phe, Fmoc-Tyr, Fmoc-Trp, Fmoc-Met, and Fmoc-Cha, and assessed their gelation efficiency at pH 7.

Photocrosslinkable triple helical protein with enhanced higher-order formation for biomaterial applications.

Bacterial collagen, produced via recombinant DNA methods, offers advantages including consistent purity, customizable properties, and reduced allergy potential compared to animal-derived collagen. Its controlled production environment enables tailored features, making it more sustainable, non-pathogenic, and compatible with diverse applications in medicine, cosmetics, and other industries. Research has focused on the engineering of collagen-like proteins to improve their structure and function.

Biomimetic design of fibril-forming non-immunogenic collagen like proteins for tissue engineering.

Collagen, a key component of extracellular matrix serves as a linchpin for maintaining structural integrity and functional resilience. Concerns over purity and immunogenicity of animal-derived collagens have spurred efforts to develop synthetic collagen-based biomaterials. Despite several collagen mimics, there remains limited exploration of non-immunogenic biomaterials with the capacity for effective self-assembly.

A Unique Temperature-Induced Reverse Supramolecular Chirality-Assisted Gel-to-Gel Transition.

Supramolecular hydrogels typically undergo a gel-to-sol transition with heat, as intermolecular interactions within the gel weaken. Although gel-to-gel transitions during heating are rare, they may occur due to minor rearrangements caused by thermal forces in the supramolecular self-assembled structure. Here, an unprecedented temperature-induced gel-to-gel transition assisted by supramolecular chiral inversion in a hydrogel system is presented.

Collagen Mimicry with a Short Collagen Model Peptide.

Mimicking triple helix and fibrillar network of collagen through collagen model peptide(CMP) with short GPO tripeptide repeats is a great challenge. Herein, a minimalistic CMP comprising only five GPO repeats [(GPO) ] is presented. This novel approach involves the fusion of ultrashort peptide with the synergetic power of π-system and β-sheet formation to short CMP (GPO) .

Impact of SiO nanoparticles on the structure and property of type I collagen in three different forms.

Silica-based nanoparticles have found application in the development of biocomposites involving reconstituted collagen in tissue engineering and wound healing, and leather modification, specifically targeting collagen fibers. However, a comprehensive investigation into the interaction between collagen-silica nanoparticles and different forms of collagen using biophysical methods remains unexplored. In this study, we examined the interaction between silica (SiO) nanoparticles and collagen in its fiber, microfibril, and monomer forms through high-resolution scanning electron microscopy, circular dichroism, Fourier-transform infrared spectroscopy, fluorescence analysis, zeta potential measurements, and turbidity assays.

Structural Insights into the Amyloid Fibril Polymorphism Using an Isotope-Edited Vibrational Circular Dichroism Study at the Amino Acid Residue Level.

Polymorphism is common in both in vitro and in vivo amyloid fibrils formed by the same peptide/protein. However, the differences in their self-assembled structures at the amino acid level remain poorly understood. In this study, we utilized isotope-edited vibrational circular dichroism (VCD) on a well-known amyloidogenic peptide fragment (NFGAIL) of human islet amyloid polypeptide (IAPf) to investigate the structural polymorphism.

Improving Hydrophobicity of Collagen with Silica Nanoparticles: Probing a Noncovalent Approach.

Collagen-based materials have a wide range of applications in wound care, tendon repair, cartilage repair, etc. Improving certain properties such as hydrophobicity can diversify the application areas. In this work, we investigated the noncovalent interactions of suitably functionalized silica nanoparticles with collagen for the possibility of improving hydrophobicity.

Rational design of antimicrobial peptide conjugated graphene-silver nanoparticle loaded chitosan wound dressing.

Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor mechanical strength, and lack of porosity and flexibility are the major cause of blood loss, delayed wound repair, and sometimes causes death during the trauma or injury. In such cases, hydrogel-based antibacterial wound dressing would be a boon to the existing dressing as the moist environment will maintain the cooling temperate and proper exchange of atmosphere around the wound. In the present study, the multifunctional graphene with silver and ε-Poly-l-lysine reinforced into the chitosan matrix (CGAPL) was prepared as a nanobiocomposite wound dressing.

Synthesis of Blue Emissive Quaternary 9,9-Disubstituted -Methyl-7-azaindole-Appended (Phenylethynyl)-fluorene Derivatives.

A highly functionalized 9,9-disubstituted (phenylethynyl)-fluorene-appended -methyl-7-azaindole derivatives has been synthesized from various fluorene propargylic alcohols and substituted-7-azaindoles using BFOEt as a catalyst. The scope of the reaction was demonstrated by selecting a range of fluorene propargylic alcohols and substituting 7-azaindoles. A plausible reaction mechanism for forming title compounds via propargylic carbocation is postulated.

A Novel Surfactant with Short Hydrophobic Head and Long Hydrophilic Tail Generates Vesicles with Unique Structural Feature.

Surfactant molecules typically have a long hydrophobic tail and a short hydrophilic head group. It remains unexplored if surfactants can have a short hydrophobic head group and a long hydrophilic tail. Designing such surfactants is a challenge as a lengthy hydrophilic tail would completely solubilize the molecules.

Functionalization of Bacterial Cellulose and Related Surfaces Using a Facile Coupling Reaction by Thermoresponsive Catalyst.

Recently, bacterial cellulose and related materials attracted significant attention for applications such as leather-like materials, wound healing materials, etc., due to their abundance in pure form and excellent biocompatibility. Chemical modification of bacterial cellulose further helps to improve specific properties for practical utility and economic viability.

Nanosized Hexagonal Boron Nitride and Polyethylene Glycol-Filled Leathers for Applications Demanding High Thermal Insulation and Impact Resistance.

Leather is a niche material used for upholsteries, gloves, and garments due to its high durability, flexibility, and softness properties. The inclusion of nanoparticles in the leather matrix provides multifunctionality for high-performance applications. Herein, we synthesized hexagonal boron nitride (h-BN) nanoparticles via a single-step hydrothermal synthesis and treated the leather after dispersing in polyethylene glycol (PEG) to yield h-BN/PEG-treated leathers.

Isotope-edited vibrational circular dichroism study reveals a flexible N-terminal structure of islet amyloid peptide (NFGAIL) in amyloid fibril form: A site-specific local structural analysis.

The short peptide fragment NFGAIL (IAPf) is a well-known amyloidogenic peptide (22-27), derived from human islet amyloid polypeptide(hIAPP), whose fibrillar structure is often used to better understand the wild-type hIAPP amyloid fibrils, associated with type II diabetes. Despite an extensive study, the fibrillar structure of IAPf at the amino acid residue level is still unclear. Herein, the vibrational circular dichroism(VCD) spectroscopic technique coupled with isotope labelling strategy has been used to study the site-specific local structure of IAPf amyloid fibrils.

Electrochemical Response of Redox Amino Acid Encoded Fluorescence Protein for Hydroxychloroquine Sensing.

The sudden rise in the demand has led to large-scale production of hydroxychloroquine (HCQ) in the global market for various diseases such as malaria, rheumatic arthritis, and systemic lupus erythematous and prophylactic treatment of early SARS-CoV-2 outbreak. Thorough monitoring of HCQ intake patients is in high demand; hence, we have developed a redox amino acid encoded fluorescent protein-based electrochemical biosensor for sensitive and selective detection of HCQ. This electrochemical biosensor is generated based on the two-electron transfer process between redox amino acid (3,4-dihydroxy-L-phenylalanine, DOPA) encoded bio-redox protein and the HCQ forms the conjugate.

Engineering microbial cells with metal chelating hydroxylated unnatural amino acids for removable of synthetic pollutants from water.

Lead (Pb) is a well-known heavy metal and toxic synthetic industrial pollutant in the ecosystem and causes severe threats to living organisms. It is paramount to develop a sustainable microbial engineering approach to remove synthetic pollutants from the environment. Genetic code engineering is emerging as an important microbial engineering tool in biosciences to biosynthesis congener protein production beyond the canonical set of natural molecules and expand the chemistries of living cells.

Building biomaterials through genetic code expansion.

Genetic code expansion (GCE) enables directed incorporation of noncoded amino acids (NCAAs) and unnatural amino acids (UNAAs) into the active core that confers dedicated structure and function to engineered proteins. Many protein biomaterials are tandem repeats that intrinsically include NCAAs generated through post-translational modifications (PTMs) to execute assigned functions. Conventional genetic engineering approaches using prokaryotic systems have limited ability to biosynthesize functionally active biomaterials with NCAAs/UNAAs.

Three-dimensional tailor-made collagen-like proteins hydrogel for tissue engineering applications.

Despite the potential tunable properties of blank slate collagen-like proteins (CLP), an alternative to animal-originated collagen, assembling them into a stable 3D hydrogel to mimic extracellular matrix is a challenge. To address this constraint, the CLP (without hydroxyproline, CLPpro) and its variants encoding functional unnatural amino acids such as hydroxyproline (CLPhyp) and 3,4-dihydroxyphenylalanine (CLPdopa) were generated through genetic code engineering for 3D hydrogel development. The CLPhyp and CLPdopa were chosen to enhance the intermolecular hydrogen bond interaction through additional hydroxyl moiety and thereby facilitate the self-assembly into a fibrillar network of the hydrogel.

Advances in nanotechnology application in biosafety materials: A crucial response to COVID-19 pandemic.

The outbreak of coronavirus disease 2019 (COVID-19) has adversely affected the public domain causing unprecedented cases and high mortality across the globe. This has brought back the concept of biosafety into the spotlight to solve biosafety problems in developing diagnostics and therapeutics to treat COVID-19. The advances in nanotechnology and material science in combination with medicinal chemistry have provided a new perspective to overcome this crisis.

A new-fangled horizon in leather process to sidestep toxic chrome and formaldehyde using hyperbranched polymer.

A novel chrome-free tanning and formaldehyde-free post tanning process with PEG-melamine base hyperbranched polymer by complexing aluminum (Al) present in aluminum sulfate for eco-friendly tanning applications. The hyperbranched polymers PEGM-400-C-Al and PEGM-600-C-Al were synthesized and characterized by FT-IR, NMR, UV, and XRD. The molecular weight of polymers was assessed by GPC and subjected to the leather process.

DMSO-allyl bromide: a mild and efficient reagent for atom economic one-pot -allylation and bromination of 2°-aryl amines, 2-aryl aminoamides, indoles and 7-aza indoles.

A mixture DMSO-allyl bromide has been developed as a reagent for an atom economic one-pot -allylation and aryl bromination under basic conditions. Utilizing this reagent, -allylation-bromination of a number of 2°-aryl amines, aryl aminoamides, indoles, and 7-aza indoles has been achieved. The scope of the substrates and limitations, the synthetic utility of the products, and a plausible reaction mechanism have been proposed.

A cyclodextrin-based macrocyclic oligosaccharide cavitand with a dual functionality limits the collagen fibrillogenesis: A possible carbohydrate-based therapeutic molecule for fibrotic diseases.

β-Cyclodextrin (β-CD), a macrocyclic oligosaccharide cavitand, is a well-known candidate for drug delivery and formulation. In this study, we extended the application of β-CD using a β-cyclodextrin sulfate (β-CDS) as a possible therapeutic for fibrotic diseases caused by excess deposition of collagen fibrils. We have strategically chosen β-CDS, which mimics the natural existence of dermatan sulfate in the extracellular matrix, for limiting collagen fibrillation.