Counterfeiting and inverse engineering of security and confidential documents, such as banknotes, passports, national cards, certificates, and valuable products, has significantly been increased, w...

Photoluminescent and Chromic Nanomaterials for Anticounterfeiting Technologies: Recent Advances and Future Challenges.

Antimicrobial resistance (AMR) is one of the greatest threats to human health that, by 2050, will lead to more deaths from bacterial infections than cancer. New antimicrobial agents, both broad-spectrum and selective, that do not induce AMR are urgently required. Antimicrobial peptides (AMPs) are a novel class of alternatives that possess potent activity against a wide range of Gram-negative and positive bacteria with little or no capacity to induce AMR. This has stimulated substantial chemical development of novel peptide-based antibiotics possessing improved therapeutic index. This review summarises recent synthetic efforts and their impact on analogue design as well as their various applications in AMP development. It includes modifications that have been reported to enhance antimicrobial activity including lipidation, glycosylation and multimerization through to the broad application of novel bio-orthogonal chemistry, as well as perspectives on the direction of future research. The subject area is primarily the development of next-generation antimicrobial agents through selective, rational chemical modification of AMPs. The review further serves as a guide toward the most promising directions in this field to stimulate broad scientific attention, and will lead to new, effective and selective solutions for the several biomedical challenges to which antimicrobial peptidomimetics are being applied.

Chemically modified and conjugated antimicrobial peptides against superbugs.

Bacterial infections caused by 'superbugs' are increasing globally, and conventional antibiotics are becoming less effective against these bacteria, such that we risk entering a post-antibiotic era. In recent years, antimicrobial peptides (AMPs) have gained significant attention for their clinical potential as a new class of antibiotics to combat antimicrobial resistance. In this review, we discuss several facets of AMPs including their diversity, physicochemical properties, mechanisms of action, and effects of environmental factors on these features. This review outlines various chemical synthetic strategies that have been applied to develop novel AMPs, including chemical modifications of existing peptides, semi-synthesis, and computer-aided design. We will also highlight novel AMP structures, including hybrids, antimicrobial dendrimers and polypeptides, peptidomimetics, and AMP-drug conjugates and consider recent developments in their chemical synthesis.

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The multifaceted nature of antimicrobial peptides: current synthetic chemistry approaches and future directions.

Recent advances in design of antimicrobial peptides and polypeptides toward clinical translation.

As a commonly used treatment method for cancer, chemotherapy is greatly limited by the side effects of chemotherapy drugs and the multiple drug resistance that develops. Nanogels are considered ideal drug carriers due to their high stability, high water content and excellent drug loading capacities. To achieve more precise and intelligent drug delivery in tumor tissues, various environmentally responsive nanogels have been widely developed. Compared to normal tissue, tumor tissue exhibits a lower pH value. Therefore, the pH gradients between the tumor microenvironment and the normal physiological environment can be used to design pH-sensitive nanogels to regulate the delivery and release of antitumor drugs. This article mainly introduces the application of pH-sensitive nanogels in cancer treatment, hoping to provide a reference for the development of cancer treatment.

pH-Sensitive nanogels for drug delivery in cancer therapy.

Polypeptides have attracted considerable attention in recent decades due to their inherent biodegradability and tunable cytocompatibility. Macromolecular design in conjunction with rational monomer composition can direct architecture, self-assembly and chemical behavior, ultimately guiding the choice of appropriate application within the biomedical field. This review focuses on the applications of polypeptides alongside the synthetic advances in the ring opening polymerization of α-amino acid N-carboxyanhydrides achieved in the past five years. Key architectures obtained through NCA ROP or in combination with other polymerization methods are reviewed, as these play an important role in the wide range of applications towards which polypeptides have been applied.

Ring opening polymerization of α-amino acids: advances in synthesis, architecture and applications of polypeptides and their hybrids.

Thermochromic materials exhibit a color change in response to a change in temperature. Creating nontoxic microcapsules containing thermochromic materials for applications in ink and film materials is historically challenging. In this study, we develop a nontoxic chlorophenol red (CPR)–water thermochromic system and its microcapsules with silicone shells via a reaction between water and octadecyltrichlorosilane (OTS) at the interface of a w/o emulsion. The obtained microcapsules exhibit a clear color change with full reversibility and are successfully used as inks by screen printing and as additives in films. Nontoxicity of both microcapsules and films is demonstrated through cell cytotoxicity assays. These features make these novel materials applicable to the next generation of intelligent sensors, coating, and food packaging materials.

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Reversible Nontoxic Thermochromic Microcapsules.

In nature, polypeptide-based materials are ubiquitous, yet their synthetic production is hampered by high cost, limited scalability, and often stringent reaction conditions. Herein an elegant approach is presented for N-carboxyanhydride ring opening polymerization (NCA ROP) of Ne-benzyloxycarbonyl-l-lysine (ZLL) and γ-benzyl-l-glutamate (BLG) NCA in continuous flow. The polymerization is initiated by primary amine initiators using N,N-dimethylformamide (DMF) as solvent. Carrying out the reaction in a silicon microflow reactor speeds up the rate of ROP (92% conversion in 40 min in flow as opposed to 6 h in batch) due to highly efficient permeation of CO2 through the reactor tubing. The polymerization strategy provides a facile, scale-up friendly alternative to traditional batch mode polymerization and has the capability of streamlining NCA ROP.

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Alicia Rasines Mazo

Papers

Ring opening polymerization of α-amino acids: advances in synthesis, architecture and applications of polypeptides and their hybrids.

Reversible Nontoxic Thermochromic Microcapsules.

Accelerated Polypeptide Synthesis via N-Carboxyanhydride Ring Opening Polymerization in Continuous Flow.

Blue LED light-activated RAFT polymerization of PEG acrylate with high chain-end fidelity for efficient PEGylation