Biomimetic peptide conjugates as emerging strategies for controlled release from protein-based materials

Biopolymers, such as collagens, elastin, silk fibroin, spider silk, fibrin, keratin, and resilin have gained significant interest for their potential biomedical applications due to their biocompatibility, biodegradability, and mechanical properties. This review focuses on the design and integration of biomimetic peptides into these biopolymer platforms to control the release of bioactive molecules, thereby enhancing their functionality for drug delivery, tissue engineering, and regenerative medicine. Elastin-like polypeptides (ELPs) and silk fibroin repeats, for example, demonstrate how engineered peptides can mimic natural protein domains to modulate material properties and drug release profiles. Recombinant spider silk proteins, fibrin-binding peptides, collagen-mimetic peptides, and keratin-derived structures similarly illustrate the ability to engineer precise interactions and to design controlled release systems. Additionally, the use of resilin-like peptides showcases the potential for creating highly elastic and resilient biomaterials. This review highlights current achievements and future perspectives in the field, emphasizing the potential of biomimetic peptides to transform biopolymer-based biomedical applications.

In vivo toxicity of chitosan-based nanoparticles: a systematic review

Chitosan nanoparticles have been extensively utilised as polymeric drug carriers in nanoparticles formulations due to their potential to enhance drug delivery, efficacy, and safety. Numerous toxicity studies have been previously conducted to assess the safety profile of chitosan-based nanoparticles. These toxicity studies employed various methodologies, including test animals, interventions, and different routes of administration. This review aims to summarise research on the safety profile of chitosan-based nanoparticles in drug delivery, with a focus on general toxicity tests to determine LD50 and NOAEL values. It can serve as a repository and reference for chitosan-based nanoparticles, facilitating future research and further development of drugs delivery system using chitosan nanoparticles. Publications from 2014 to 2024 were obtained from PubMed, Scopus, Google Scholar, and ScienceDirect, in accordance with the inclusion and exclusion criteria.The ARRIVE 2.0 guidelines were employed to evaluate the quality and risk-of-bias in the in vivo toxicity studies. The results demonstrated favourable toxicity profiles, often exhibiting reduced toxicity compared to free drugs or substances. Acute toxicity studies consistently reported high LD50 values, frequently exceeding 5000 mg/kg body weight, while subacute studies typically revealed no significant adverse effects. Various routes of administration varied, including oral, intravenous, intraperitoneal, inhalation, and topical, each demonstrating promising safety profiles.

Solvent volatilization annealing-prepared Janus film with asymmetric bioadhesion and inherent biological functions to expedite oral ulcer healing

Fabrication of layered bioadhesives with asymmetric bioadhesion, on-demand detachment and inherent biological functions remains a great challenge. This work reports a novel and generalizable solvent volatilization-induced annealing (SVA) strategy to prepare a Janus film with an integrated dual layer structure, asymmetric adhesion, on-demand detachment and inherent biological functions. Depositing polyvinyl pyrrolidone/caffeic acid/lipoic acid (PVP/CA/LA) ethanol solutions onto an ethylcellulose (EC) layer and applying SVA strategy can integrate two layers in molecular-level to obtain the dual-layered Janus film. Porous PVP/p(CA-LA) surface pressed onto wet tissues can absorb interfacial water to form tight tissue contact, and their functional groups can form abundant bonds to induce robust bioadhesion. In contrast, dense EC surface limits water absorption and exhibits minimal adhesion of proteins, cells and tissues. Furthermore, the adhered Janus film can be detached by using a glutathione/sodium bicarbonate solution. Additionally, CA and LA provide the film with desired antibacterial, antioxidant, and anti-inflammatory properties. Finally, by providing the antibacterial and anti-inflammatory microenvironment, the Janus film promotes angiogenesis and significantly expedites the healing of the oral ulcers in rats. This work not only introduces a novel approach for preparing multi-layered and asymmetric materials, but also paving the way for developing adhesive materials with inherent biological functions.

Evaluation of the effects of cartilage decellularized ECM in optimizing PHB-chitosan-HNT/chitosan-ECM core-shell electrospun scaffold: Physicochemical and biological properties

Cartilage regeneration is still a highly challenging field due to its low self-healing ability. This study used a core-shell electrospinning technique to enhance cartilage tissue engineering by incorporating cartilage extracellular matrix (ECM). The core of fibers included poly(3-hydroxybutyrate)-Chitosan (PHB-Cs) and Halloysite nanotubes. The shell of fibers consisted of Cs and ECM (0, 1, 3, 5 wt%). Subsequently, the scaffolds were named 0E, 1E, 3E, and 5E. The study aimed to assess the impact of ECM on cellular behavior and chondrogenesis. Our findings indicate that ECM reduced fiber diameter from 775 nm for the 0E scaffold to 454 nm for the 1E scaffold. Water contact angle measurements revealed an increasing trend by ECM addition, from 42° for 0E to 67° for 1E. According to mechanical analysis, the 1E scaffold represented the highest strength (5.81 MPa) and strain (3.17%). Based on these analyses, the 1E was considered the optimum scaffold. MTT analysis showed cell viability of over 80% for the 0E and 1E. Also, the gene expression level was assessed for Collagen II, Aggrecan, SOX 9, and Collagen X. The results represented that in the 1E scaffold Collagen II, Aggrecan, and SOX 9 were more upregulated at the end of the 21st day. However, in the 1E scaffold collagen X, as a hypertrophy marker, was downregulated at the end of the experiment. Overall, these results confirmed the potential of the 1E scaffold to be introduced as a promising cartilage tissue engineering scaffold for further studies.

Fully biodegradable ion-induced silk fibroin-based triboelectric nanogenerators with enhanced performance prevent muscle atrophy

Applying electrical stimulation (ES) on nerve or muscle denervation can significantly restore the nerve function and prevent muscle atrophy. The triboelectric nanogenerator (TENG) can couple the mechanical energy and electrical energy for ES. However, the triboelectric performance of fully biodegradable TENGs and the effect of ES need to be optimized and verified. Here, the triboelectric performance of silk fibroin (SF) is regulated by ions to fabricate SF-TENGs with full biodegradability, good biocompatibility, and excellent output. This SF-TENG shows a good electrostimulation recovery effect and is used for function restoration of the injured sciatic nerve and innervated muscle. Li+ effectively improves the dielectric constant and increases the positively charged ability of SF. The highest output power density of SF-TENG is 128 mW/m2, which is superior to most reported fully biodegradable TENGs. The morphology, protein expression levels, neural/muscular function are assessed to evaluate the recovery of damaged nerves and innervated muscle. The function restoration of the injured nerve and innervated muscle under ES of SF-TENG is significantly close to the normal nerve and muscle. This TENG has great potential to achieve in vivo energy generation, ES, and biodegradability as an implantable electrical stimulator for the therapy of nerve, muscle, and tissue injury.

A non-crystallization-driven strategy for the preparation of non-spherical polymeric nanoparticles

To fabricate precisely defined non-spherical nanostructures like those widely exist in the biological domain by self-assembly of synthetic polymers without employing crystallization-driven forces is still a great challenge. In this study, we report a strategy to fabricate nanoparticles with advanced hierarchical architectures using styrene and methacrylic as monomers and maleamic acid-α-methyl styrene copolymer as a macroinitiator by polymerization-induced self-assembly (PISA). The structure of the prepared particles changed from common spherical micelles to cubes with edge lengths ranging from 50 to 200 nm when the solvent was 50 wt% ethanol in water and the monomer molar ratio of styrene to 2-hydroxyethyl methacrylate was 3:1. The growth of the cubic nanoparticles exhibited an interesting self-assembly process, initially forming vesicles with irregular cubes inside them. As the polymerization progressed, the inner cubes escaped from the vesicles and finally generated well-defined cubic nanoparticles. Wide-angle X-ray scattering (WAXS) results of the cubic nanoparticles indicated that no crystalline structure existed. The formation mechanism of the cubic nanoparticles was elucidated via density functional theory (DFT) calculations. This strategy was further applied to various monomers, and its universality was confirmed by successful fabrication of different non-spherical nanoparticles such as rectangles, fusiform platelets, and triangular pyramids.

Bridge-to-drain: How nanoparticles can promote coalescence in model polymer blends

HYPOTHESIS

Multiphase liquids with a droplet-in-matrix morphology are ubiquitous in many industries, from food to cosmetics and pharmaceuticals to plastics. The challenge is to control the average droplet size, which is a key parameter for the performance of the material. Nanoparticles at the droplet-matrix interface make it possible to stabilize polymer blends against coalescence. However, it has been shown that very low amounts of nanoparticles can have the opposite effect and surprisingly promote coalescence. Regardless of whether this phenomenon is desirable or not, it is important to understand it and potentially utilize it for rational design of multiphase fluids.

EXPERIMENTS

We use microfluidics to unveil the mechanism of nanoparticle-induced coalescence in a model blend of polydimethylsiloxane in poly(iso)butylene (PDMS/PB 4/96 vol/vol) containing tiny amounts (up to about 0.2 wt%) of zinc oxide (ZnO) nanoparticles driven at the droplet-matrix interface via a two-step mixing protocol.

RESULTS

Despite negligible effects on rheology and interfacial energy, the nanoparticles significantly promote coalescence. Analysis of hundreds of coalescence events revealed that the nanoparticles bridge colliding droplets and keep them in contact long enough to allow drainage of the matrix film even when the collisions occur at unfavorable angles where bare droplets do not coalesce. This novel "bridge-to-drain" mechanism requires that (i) the droplets are only partially covered by the particles and (ii) the latter have the ability to bridge droplets. A dimensionless critical surface coverage fraction was defined, above which the nanoparticles stop promoting coalescence and start stabilizing the microstructure.

DFT-driven design of efficient dual-atom electrocatalysts for lithium-sulfur batteries: Fe dimers supported on phthalocyanine

Lithium-sulfur (Li-S) batteries have garnered widespread attention and research due to their high theoretical capacity and energy density. However, their commercialization is hindered by several issues, including low electrical conductivity of the sulfur electrode, the polysulfide shuttle effect, and slow charge-discharge kinetics. Double-atom transition metal phthalocyanines (M2-Pc), which are large conjugated compounds with M2-N12 rings, have potential application value in electrochemical catalysis due to their unique electronic structures and metal coordination properties. Through a five-step screening strategy, the study investigated the catalytic activity of a series of M2-Pc (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) towards S8/LiPSs. The results show that Fe2-Pc exhibits the best catalytic activity, attributed to its low Gibbs free energy (0.88 eV) in the rate-limiting step of the discharge reaction and its low decomposition energy barrier (0.72 eV) of Li2S during the charge reaction. Additionally, the integral of crystal orbital Hamiltonian population (ICOHP) can serve as a descriptor for the catalytic activity related to the decomposition energy barrier of Li2S during the charging process. This provides theoretical guidance for the design of Li-S battery cathode materials and further experimental work.

Two-dimensional unilamellar cation-deficient metal oxide nanosheet incorporated composite polymer electrolytes for all-solid-state lithium metal batteries

Composite polymer electrolytes (CPEs) are considered among the leading contenders for next-generation all-solid-state lithium-metal batteries. However, CPEs simultaneously face multiple significant challenges, including reduced ion transference number, insufficient ionic conductivity, and poor cycling stability, which severely limit their practical applicability. Herein, we have designed a multifunctional unilamellar inorganic nanosheets (Ti0.87O2) additive for CPEs with cationic defects which is capable of simultaneously addressing all aforementioned challenges. The atomic Ti vacancies facilitate the direct passage of lithium ions through the nanosheets, and the monolayer structure accelerates the diffusion of lithium ions through the nanosheets. In addition, the atomic Ti vacancies can promote lithium salt dissociation while hindering anion transport. These two features of Ti0.87O2 nanosheet additives collectively enhance the ionic conductivity and lithium transference number. Furthermore, benefiting from the large specific surface area and defects, the Ti0.87O2 nanosheets can accommodate a high density of lithium ions, thereby releasing them to mitigate the polarization and elongating the Sand's time, which ultimately improves the battery's cycling stability. Finally, the ionic conductivity of CPE incorporated with this additive has improved by 42 times. Furthermore, the Li||Li symmetric cell demonstrates stable cycling for over 700 h at 0.1 mA cm-2. This work provides a new avenue for designing novel additives to develop solid-state electrolytes that offer excellent ionic conductivity and stability.

Spectroscopic, electrical, and cytocompatibility properties of luminescent (metal nanoparticle/polyaniline) composites

In recent years, the integration of metallic nanoparticles with conductive polymers has gained significant attention for biomedical applications, including biosensors and therapeutic agents. Here, we synthesized hybrid nanocomposites of polyaniline (PANI) with copper (Cu) and silver (Ag) nanoparticles using a straightforward and scalable one-pot synthesis method. These composites were characterized by a range of techniques, including UV-vis, Fourier Transform Infrared (FTIR) spectroscopy, Zeta Potential measurements, Dynamic Light Scattering (DLS), and photoluminescence (PL). Our analysis confirmed that the composites consist of the leucoemeraldine form of PANI, which exhibited dual fluorescence emission at 342 nm (UV region) and 667 nm (visible region), highlighting a synergistic interaction between the metal nanoparticles and PANI chains. The fluorescence quantum yield was determined to be 8.80 % for Cu/PANI and 10.05 % for Ag/PANI, indicating efficient luminescence and tunability based on the metal used. The cytocompatibility was evaluated through MTT assays on four cell lines (Vero cells, macrophages, HeLa cells, and fibroblasts), showing favorable biocompatibility across most cell types. Notably, macrophages (CC50 = 353.4 μg/mL) and Vero cells (CC50 = 324.5 μg/mL) showed higher sensitivity to Cu/PANI treatment, suggesting selective interactions compared to Ag/PANI and other similar composites reported in the literature. These results demonstrate that Cu/PANI and Ag/PANI composites combine promising fluorescence properties with cytocompatibility, making them suitable candidates for diverse biomedical applications, such as fluorescent markers, biosensors, and therapeutic agents.

PCL-fibrin-alginate hydrogel based cell co-culture system for improving angiogenesis and immune modulation in limb ischemia

Stem cell therapy has demonstrated promise in regenerative medicine due to their ability to differentiate into various cell types and secrete growth factors. However, challenges such as poor survival rate of transplanted cells under ischemic and immune conditions limit its effectiveness. To address these issues, we developed a polycaprolactone (PCL)-fibrin-alginate matrix hydrogel, which combines adipose-derived stem cells and human umbilical vein endothelial cells with a PCL fiber, encapsulated within fibrin and alginate hydrogel to enhance cell survival, proliferation, and immune modulation. This structure offers protection to the encapsulated cells, supports angiogenesis, and modulates the immune response, significantly improving therapeutic outcomes in a mouse model of hindlimb ischemia. Our in vitro and in vivo results demonstrate the scaffold's ability to support cell viability, promote angiogenesis, and modulate inflammatory responses, indicating its potential as a promising platform for ischemic tissue repair and regenerative medicine. This innovative approach to cell-based therapy highlights the importance of scaffold design in enhancing the therapeutic efficacy of stem cell treatments for ischemic diseases.

Herbal micelles-loaded ROS-responsive hydrogel with immunomodulation and microenvironment reconstruction for diabetic wound healing

Persistent inflammation is a major cause of diabetic wounds that are difficult to heal. This is manifested in diabetic wounds with excessive reactive oxygen clusters (ROS), advanced glycation end products (AGE) and other inflammatory factors, and difficulty in polarizing macrophages toward inhibiting inflammation. Berberine is a natural plant molecule that inhibits inflammation; however, its low solubility limits its biological function through cytosis. In this study, we designed F127 micelles to encapsulate berberine with the aim of improving its solubility and bioavailability. Meanwhile, in order to achieve effective drug delivery at the wound site, we designed an injectable ferrocene-cyclodextrin self-assembled oxidation-reactive supramolecular hydrogel drug delivery system. Cellular experiments have shown that the hydrogel can reduce intracellular ROS and AGE production, attenuate cellular damage, promote macrophage polarization toward inhibition of inflammation, and reduce the secretion of inflammatory factors. In an animal model of diabetic mice, this hydrogel dressing reduces the level of inflammation in diabetic wounds, optimizes collagen deposition in diabetic wounds, and ultimately achieves high-quality diabetic wound healing. The work offers a straightforward and effective solution to the challenge of administering hydrophobic anti-inflammatory agents in the context of diabetic wound therapy.

Fabrication of piezoelectric/conductive composite nerve conduits for peripheral nerve regeneration

Due to the complex regenerative microenvironment after peripheral nerve injury (PNI), developing a piezoelectric/conductive composite nerve guidance conduit (NGC) for repairing nerve defects remains a great challenge. The conductivity and piezoelectricity have been separately demonstrated to enhance the repair of PNI, yet there is a paucity of studies investigating the synergistic effects of both functions. Herein, a piezoelectric/conductive nerve conduit composed of chitosan (CS), reduced graphene oxide (rGO), and poly-L-lactic acid (PLLA) was fabricated, which provided the conductivity, mechanical support and piezoelectricity. Tensile strength, conductivity, antibacterial activity, and cell viability of piezoelectric/conductive composite NGCs were evaluated. Piezoelectric/conductive composite NGCs exhibited electrical signal output capability and conductive performance. Moreover, rGO significantly promoted cell proliferation and adhesion. Overall, the piezoelectric/conductive CS/rGO/PLLA nerve conduit shows great promise as a potential treatment of PNI.

3D printing of starch-lipid-protein ternary gel system: The role played by protein

This study investigated the printability of a typical food ternary (starch-lipid-protein) gel system and revealed the critical role of protein. The results revealed that a higher content of α-helix and a lower content of random coil in proteins positively impacted the printing accuracy of the ternary gel system. Higher α-helix content in proteins increased the shear rate at the nozzle, ensuring smooth extrusion during 3D printing while also reducing the gel velocity and filament expansion, which led to smoother filament surfaces. Moreover, higher α-helix content and lower random coil content in proteins increased V-type crystalline structures, average molecular size (Rh), and amylose (AM) chains with 100 < X ≤ 1000, while decreasing amylopectin (AP) chains with 6 < X ≤ 12 in starch. These multi-scale structural changes increased A23 content, leading to an increase in the storage modulus of the gel system and improving the mechanical property of 3D printed products, ultimately enhancing printing accuracy.

"Monitor-and-treat" that integrates bacterio-therapeutics and bio-optics for infected wound management

Wound infections are one of the major threats to human health, accounting for millions of deaths annually. Real-time monitoring, accurate diagnosis, and on-demand therapy are crucial to minimizing complications and saving lives. Herein, we propose a "monitor-and-treat" strategy for infected wound management by integrating the emerging development of bacterio-therapeutics and bio-optics. The upper layer consists of gelatin methacryloyl (GelMA)-collagen III methacryloyl (Col3MA) (GC), Reuterin (Reu) isolated from the probiotic Lactobacillus reuteri (L. reuteri) and microfluidic safflower polysaccharide (SPS)@GelMA microspheres using 3D printing technology. The lower layer is made of acryloylated glycine (ACG) hydrogel with tissue adhesion capability, which enables the hydrogel to adapt to the movement and stretching of the skin. By integrating temperature-sensitive polydimethylsiloxane (PDMS) optical fibers, the ACG-GC/Reu/SPS-PDMS hydrogel could accurately and steadily sense and send wound temperature information to intelligent devices for real-time monitoring of the healing status ("monitor"). The double-layered hydrogel not only inhibited bacterial survival and colonization (97.4 % against E. coli and 99 % against S. aureus), but also exhibited remarkable hemostatic properties. Furthermore, it was conducive to L929 cell proliferation and pro-angiogenesis, and promoted the polarization of pro-inflammatory M1 macrophages to the anti-inflammatory M2-phenotype, therefore creating a favorable immune microenvironment at the wound site. Animal experiments using SD rats and Bama minipigs demonstrated that this hydrogel promoted wound closure, directed polarization to M2 macrophages, alleviated inflammation, enhanced neovascularization, therefore accelerating infected wound healing ("treat"). In addition, RNA-Seq analysis revealed the mechanism of action of ACG-GC/Reu/SPS-PDMS hydrogel in modulating key signaling pathways, including down-regulation of AMPK, IL-17, and NF-κB signaling pathways, activation of NLRP3 inflammatory vesicles, and enrichment of MAPK, TGF-β, PI3K-Akt, TNF, and VEGF signaling pathways. The modulation of these signaling pathways suggests that hydrogels play an important role in the molecular mechanisms that promote wound healing and tissue regeneration. Therefore, the design of this study provides an innovative and multifunctional bandage strategy that can significantly improve pathologic diagnosis and wound treatment.

Robust polyaniline coating magnetic biochar nanoparticles for fast and wide pH and temperature range removal of nanoplastics and achieving label free detection

Nanoplastics as an emerging pollutant are ubiquitous in water and still not easy to measure and remove. In this regard, polyaniline coating magnetic biochar nanoparticles constructed by pyrolysis of ferrate pretreated bagasse and ball milling and coating surface with polyaniline (PA@MBCBM) were tested for their capability to attach and remove polystyrene nanoplastics in water. Porousness and rich functional groups and positive charging property of PA@MBCBM was responsible for fast, high capacity and robust attaching of nanoplastics. 94.9 % - 99.0 % of nanoplastics were removed at wide range of pH conditions (1 - 10) and PA@MBCBM was reusable for seven times with less changing of performance, and maximum adsorption capacities reached 276.24 - 334.45 mg/g at both cold and warm temperatures (5 - 35 °C). Moreover, taking advantages of efficient nanoplastics adhesion, high conductivity and electrochemical activity, the PA@MBCBM, was tested to fabricate a label free screen-printed electrode for nanoplastics detection, and achieved reasonable sensitivity with the lowest detection limit being 1.26 μg/L. In addition, exceptional performances of adsorption and detection in real water samples were also successfully realized. The proposed PA@MBCBM having dual function of robust and efficient adsorption removal, and label free and sensitive determination of nanoplastics, would be greatly constructive for reliable, cost effective and effective control and monitoring of the nanoplastics contamination.

4D printing polymeric biomaterials for adaptive tissue regeneration

4D printing polymeric biomaterials can change their morphology or performance in response to stimuli from the external environment, compensating for the shortcomings of traditional 3D-printed static structures. This paper provides a systematic overview of 4D printing polymeric biomaterials for tissue regeneration and provides an in-depth discussion of the principles of these materials, including various smart properties, unique deformation mechanisms under stimulation conditions, and so on. A series of typical polymeric biomaterials and their composites are introduced from structural design and preparation methods, and their applications in tissue regeneration are discussed. Finally, the development prospect of 4D printing polymeric biomaterials is envisioned, aiming to provide innovative ideas and new perspectives for their more efficient and convenient application in tissue regeneration.

Electroactive membranes enhance in-situ alveolar ridge preservation via spatiotemporal electrical modulation of cell motility

Post-extraction alveolar bone resorption invariably compromises implant placement and aesthetic restoration outcomes. Current non-resorbable membranes exhibit limited efficacy in alveolar ridge preservation (ARP) due to insufficient cell recruitment and osteoinductive capabilities. Herein, we introduce a multifunctional electroactive membrane (PPy-BTO/P(VDF-TrFE), PB/PT) designed to spatiotemporally regulate cell migration and osteogenesis, harmonizing with the socket healing process. Initially, the membrane's endogenous-level surface potential recruits stem cells from the socket. Subsequently, adherent cell-migration-triggered forces generate on-demand piezopotential, stimulating intracellular calcium ion fluctuations and activating the Ca2+/calcineurin/NFAT1 signaling pathway via Cav3.2 channels. This enhances cell motility and osteogenic differentiation predominantly in the coronal socket region, counteracting the natural healing trajectory. The membrane's self-powered energy supply, proportional to cell migration velocity and manifested as nanoparticle deformation, mitigates ridge shrinkage, both independently and in conjunction with bone grafts. This energy-autonomous membrane, based on the spatiotemporal modulation of cell motility, presents a novel approach for in-situ ARP treatment and the development of 4D bionic scaffolds.

Leveraging self-signal amplifying poly(acrylic acid)/polyaniline electrodes for label-free electrochemical immunoassays in protein biomarker detection

Accurate quantification of specific biomarkers is essential for clinical diagnosis and evaluating therapeutic efficacy. A self-signal-amplifying poly(acrylic acid) (PAA)/polyaniline (PANI) film-modified disposable and cost-effective screen-printed carbon electrode (SPCE) has been developed for constructing new label-free immunosensors targeting two model biomarkers: human immunoglobulin G (IgG) and alpha-fetoprotein (AFP). The electrochemically deposited PAA/PANI film on the SPCE serves a dual function: both a bio-immobilization support and a signal amplifier, enhancing biomarker detection sensitivity and efficiency. The self-signal amplification properties of PANI streamline the detection process. At the same time, the high-density surface carboxyl groups from embedded PAA enable covalent conjugation with capture antibodies (anti-IgG and anti-AFP). Subsequently, antibody-immobilized PAA/PANI film-modified SPCEs, as immunosensors, successfully detect IgG and AFP without the need for external redox probes. The reductions in the electrochemical PANI signals of the immunosensors are linearly proportional to the logarithm of IgG and AFP concentrations. The proposed immunosensors exhibit sufficiently wide ranges of calibration curves from 0.10 to 50 ng mL-1, with limits of detection of 0.080 ng mL-1 for IgG and 0.090 ng mL-1 for AFP. The sensors exhibit satisfactory sensitivity and selectivity, indicating their potential for accurate and reliable detection.

Development and characterization of potential antibacterial biocomposites: Lysozyme-loaded cellulose-alginate materials

The objective of this study was to design and characterize novel biocomposites based on modified cellulose/alginate oligosaccharides loaded with hen egg lysozyme (CLm/AOS/Lyz) as a potential alternative to combat bacterial proliferation. An antimicrobial enzyme, lysozyme, was immobilized within polymeric matrices to enhance its bactericidal capacity and stability. The biocomposites synthesized at pH levels 3, 5, and 8 (CLm/AOS/Lyz3, CLm/AOS/Lyz5, and CLm/AOS/Lyz8, respectively) were analyzed using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), and energy-dispersive X-ray spectroscopy (EDS). Results demonstrated successful lysozyme conjugation to the biocomposite without altering its secondary structure or stability. The biocomposites exhibited irregular morphologies and strong adhesion between CLm/AOS and Lyz, with CLm/AOS/Lyz5 showing the highest nitrogen composition and protein content (2086.43 ± 100.90 µg of bovine serum albumin equivalents). Antibacterial assays revealed significant log reductions in viable E. faecalis cells for CLm/AOS/Lyz3 and CLm/AOS/Lyz5 (5.72 ± 0.17 and 5.78 ± 0.24 respectively), concerning the blank (8.04 ± 0.07), even comparable to free lysozyme (5.85 ± 0.35). However, no reduction in viable cell counts was observed for Gram-negative bacteria. This work highlights the potential of lysozyme-loaded cellulose-alginate biocomposites as novel antibacterial agents for effective applications in pharmaceutical and food technology fields.

Optimizing the pore environment in biological metal-organic frameworks through the incorporation of hydrogen bond acceptors for inverse ethane/ethylene separation

The development of efficient adsorbents for the selective separation of ethane (C2H6) and ethylene (C2H4) is essential for the cost-effective production of high-purity ethylene. Here, we employ a pore engineering strategy to optimize the pore environment of biological metal-organic frameworks (MOFs) by incorporating hydrogen bond receptors to enhance the inverse separation efficiency of C2H6 and C2H4. Compared to the isomorphic Cu-AD-SA, the methyl-functionalized Cu-AD-MSA and Cu-AD-DMSA not only provide suitable pore confinement but also offer additional binding sites, thus creating an optimal environment for strong interactions with C2H6 (AD = adenine, SA = succinic acid, MSA = 2-methylsuccinic acid, and DMSA = 2,2-dimethylsuccinic acid). Adsorption results show that Cu-AD-DMSA exhibits remarkable C2H6/C2H4 selectivity (up to 2.4) as well as outstanding C2H6 adsorption capacity (3.63 mmol g-1), surpassing most reported C2H6-selective MOFs. Theoretical calculations combined with in situ infrared spectroscopy reveal that the synergetic effect of suitable pore confinement, amino groups, and functional surfaces decorated with multiple methyl binding sites provides strong and multipoint interactions for C2H6. Breakthrough experiments demonstrate that Cu-AD-DMSA exhibits exceptional performance in separating binary C2H6/C2H4 gas mixtures. The high chemical and thermal stability, scalable synthesis, and economic viability of Cu-AD-DMSA illustrate its potential as a candidate for C2H6/C2H4 separation application.

Recent progress in alginate-based nanocomposites for bone tissue engineering applications

Approximately 5-10 % of fractures are associated with non-union, posing a significant challenge in orthopedic applications. Addressing this issue, innovative approaches beyond traditional grafting techniques like bone tissue engineering (BTE) are required. Biomaterials, combined with cells and bioactive molecules in BTE, are critical in managing non-union. Alginate, a natural polysaccharide, has gained widespread recognition in bone regeneration due to its bioavailability, its ability to form gels through crosslinking with divalent cations, and its cost-effectiveness. However, its inherent mechanical weaknesses necessitate a combinatorial approach with other biomaterials. In recent years, nanoscale biomaterials have gained prominence for bone regeneration due to their structural and compositional resemblance to natural bone, offering a supportive environment that regulates cell proliferation and differentiation for new bone formation. In this review, we briefly outline the synthesis of alginate-based nanocomposites using different fabrication techniques, such as hydrogels, 3D-printed scaffolds, fibers, and surface coatings with polymer, ceramic, carbon, metal, or lipid-based nanoparticles. These alginate-based nanocomposites elicit angiogenic, antibacterial, and immunomodulatory properties, thereby enhancing the osteogenic potential as an insightful measure for treating non-union. Despite the existence of similar literature, this work delivers a recent and focused examination of the latest advancements and insights on the potential of alginate-based nanocomposites for BTE applications. This review also underscores the obstacles that alginate-based nanocomposites must overcome to successfully transition into clinical applications.

Synthesis and use of thermoplastic polymers for tissue engineering purposes

Thermoplastic polymers provide a versatile platform to mimic various aspects of physiological extracellular matrix properties such as chemical composition, stiffness, and topography for use in cell and tissue engineering applications. In this review, we provide a brief overview of the most promising thermoplastic polymers, and in particular the thermoplastic polyesters, such as poly(lactic acid), poly(glycolic acid), and polycaprolactone, and the thermoplastic elastomers, such as polyurethanes, polyhydroxyalkanoates, and poly(butyl cyanoacrylate). A particular focus has been made on the synthesis processes, the processability and the biocompatibility. We also discuss how these materials can be applied in tissue engineering, mimicking tissues' structure and function, and stimulate mesenchymal stem cells differentiation and mechanotransduction.

Targeting lipid metabolism via nanomedicine: A prospective strategy for cancer therapy

Lipid metabolism has been increasingly recognized to play an influencing role in tumor initiation, progression, metastasis, and therapeutic drug resistance. Targeting lipid metabolic reprogramming represents a promising therapeutic strategy. Despite their structural complexity and poor targeting efficacy, lipid-metabolizing drugs, either used alone or in combination with chemotherapeutic agents, have been employed in clinical practice. The advent of nanotechnology offers new approaches to enhancing therapeutic effects, includingthe targeted delivery and integration of lipid metabolic reprogramming with chemotherapy, photodynamic therapy (PDT), and immunotherapy. The integrated nanoformulation, nanomedicine, could significantly advance the field of lipid metabolism therapy. In this review, we will briefly introduce the concept of cancer lipid metabolism reprogramming, then elaborate the latest advances in engineered nanomedicine for targeting lipid metabolism during cancer treatment, and finally provide our insights into future perspectives of nanomedicine for interference with lipid metabolism in the tumor microenvironment.

A starch‑sodium alginate interpenetrating network enhances the structure, texture, and starch digestibility of extruded buckwheat noodles: Regulatory effects of mannuronate/guluronate ratios and calcium ion concentrations

The regulatory effects of different mannuronate/guluronate ratios in sodium alginate (SA) and calcium ion (Ca2+) concentrations on the structure and properties of starch-SA interpenetrating polymer network (IPN)-enhanced extruded buckwheat noodles were investigated. The thermal stability of buckwheat noodles was improved by increasing the G block proportion, and 1% Ca2+ concentration led to the highest thermal stability. With increasing G proportion and Ca2+ concentration, cooking loss and elongation at break of extruded noodles gradually decreased. The cooking time initially decreased and then increased. Noodle hardness, chewiness, and breaking strength significantly increased. In vitro starch digestion showed that when the SA M/G ratio was 1:2 and the Ca2+ concentration was 1%, the predicted glycemic index of noodles was the lowest and the resistant starch content was the highest. According to curve fitting based on the sensory evaluation results, the overall noodle acceptability was higher when hardness was between 3800 and 5200 g.

A general orthogonal functionalization strategy for tailoring zwitterionic polymers with adjustable isoelectric points

Zwitterionic polymers, bearing a pair of oppositely charged groups in their repeat units, have demonstrated significant promise in both biomedical and engineering fields. Tunability of isoelectric points (IEPs) is of great value for bio-applications as it relates to key properties such as the surface charge reversal behavior, biocompatibility and the affinity to biomacromolecules. However, zwitterionic polymers with adjustable IEPs are difficult to obtain due to the fixed combination of ion pairs such as carboxybetaine-, sulfobetaine- and phosphorylcholine-based structures. To address this issue, we present a general approach to tailor zwitterionic polymers with adjustable IEPs. By developing an orthogonal functionalization strategy with sequence-controlled alternating polyesters, a series of zwitterionic polymers featuring customizable ion pairs were synthesized. This strategy, which involves aza-Michael addition and thiol-ene reaction, enables precise control over the alternating sequence of cations and anions, thereby allowing the generation of customizable ion pairs in each repeat unit. By forming block copolyesters with a hydrophobic polycaprolactone block, these polymers self-assemble into nanoparticles with tunable IEPs (e.g., 6.03, 6.37, and 6.54) and surface-charge-reversal properties, responding to physiological (pH 7.4) and tumor microenvironment (pH 6.5 ∼ 6.9) conditions. Notably, PCL54-b-P(MA-alt-AGE-g-Pip/NAC)9 (PPS3) nanoparticles, with the optimal IEP values, exhibited remarkable efficacy in inhibiting murine melanoma tumors in vivo when loaded with curcumin. This innovative approach holds promise for developing biocompatible and biodegradable drug delivery systems with tailored properties for potential clinical applications.

Effective charge of high-generation PAMAM dendrimers in the adsorbed state

The adsorption of macromolecules onto charged surfaces is an ubiquitous process in nature and industrial processes; it has, for example, important implications for surface modification and sensors in analytics. In the case of proteins and some polyelectrolytes, such as dendritic ones, the adsorption process and the resulting final coverage can be described within the framework of the random sequential adsorption (RSA) model. To provide a quantitative description of the intermolecular interaction potential, the effective charge of the molecules is of great importance. The incorporation of charge effects results in the so-called extended or electrostatic RSA model. Here, it is demonstrated for poly(amidoamine) (PAMAM) dendrimers of generation 10 that the influence of the substrate on the effective charge must be considered. Streaming potential measurements of PAMAM G10 adsorbed onto mica and silica showed that the effective charge differed significantly for both substrates. Moreover, for substrates whose surface charge varies with pH, the effective charge varies not only by the titration of the ionizable groups of the polyelectrolytes but also due to the electrostatic interaction with the substrate. A first estimation to account for these effects is provided.

Unraveling the anti-biofouling mechanisms of slippery liquid-infused porous surface from molecular interaction perspective

Newly developed slippery liquid-infused porous surfaces (SLIPS) exhibit highly effective anti-fouling performance without harming organisms, making them a promising solution for both environmental and material protection. However, previous studies have primarily understood the anti-fouling effects of SLIPS from a mechanical perspective, neglecting the atomic interactions involved in the anti-fouling process. In this study, we combined microbiological experiments with multi-scale simulations to elucidate the microscopic mechanisms behind the unique anti-biofouling effects of SLIPS. After developing SLIPS with robust liquid-repellency, we characterized its physical and chemical properties and demonstrated its superior effectiveness in preventing Pseudomonas aeruginosa attachment. To probe the initial contact during bacterial attachment, all-atom molecular dynamics (MD) simulations were conducted, revealing that the liquid-liquid interface suppresses the effective pilin adhesion on SLIPS. Further analysis through steered MD, ab initio MD, and density functional theory calculations revealed that the flexible siloxane backbone and the non-polar nature of silicone oil molecules enhance the diffusivity of interfacial water and lead to the continuous nanoscale fluctuation of liquid-liquid interface, thus inhibiting the role of protein dynamics in promoting bio-adhesion. These novel insights into the characteristics of liquid-liquid and nano-bio interface during the anti-biofouling process of SLIPS may promote the future development of bio-inspired functional surfaces.

Adsorption characteristics of individual and binary mixture of ciprofloxacin antibiotic and lead(II) on synthesized bamboo-biochar

Adsorption of individual and a binary mixture of ciprofloxacin antibiotic (CFX) and lead ion, Pb(II) on bamboo biochar was investigated in this study. Bamboo biochar which was successfully fabricated by pyrolysis was carefully characterized by XRD, SEM, TEM, BET, FT-IR, XPS and zeta potential measurements to confirm the porous structure and high specific surface area of 134 m2 g-1. Individual and simultaneous adsorption of CFX and Pb(II) on synthesized bamboo biochar was systematically studied by batch technique. The optimum experimental parameters for CFX and Pb(II) simultaneous adsorption were pH 6, 5.0 mg mL-1 bamboo-biochar dosage, contact time 120 min while that were found to be, adsorbent dosage of 2.5 mg mL-1 and 60 min contact time, pH 3 for CFX and pH 4 for Pb(II) individual adsorption. The maximum adsorption efficiencies of binary mixture CFX and Pb(II) on bamboo biochar were achieved 99.9 and 90.8%, respectively while the very high adsorption capacities fitted by Langmuir model were found to be 183.6 and 285.7 mg g-1 for Pb(II) and CFX, respectively. Adsorption mechanisms of CFX and Pb(II) on bamboo biochar were discussed in details based on surface charge changes and isothermal data.

A coarse-grained model for aqueous two-phase systems: Application to ferrofluids

Aqueous two-phase systems (ATPSs), phase-separating solutions of water soluble but mutually immiscible molecular species, offer fascinating prospects for selective partitioning, purification, and extraction. Here, we formulate a general Brownian dynamics based coarse-grained simulation model for an ATPS of two water soluble but mutually immiscible polymer species. Including additional solute species into the model is straightforward, which enables capturing the assembly and partitioning response of, e.g., nanoparticles (NPs), additional macromolecular species, or impurities in the ATPS. We demonstrate that the simulation model captures satisfactorily the phase separation, partitioning, and interfacial properties of an actual ATPS using a model ATPS in which a polymer mixture of dextran and polyethylene glycol (PEG) phase separates, and magnetic NPs selectively partition into one of the two polymeric phases. Phase separation and NP partitioning are characterized both via the computational model and experimentally, under different conditions. The simulation model captures the trends observed in the experimental system and quantitatively links the partitioning behavior to the component species interactions. Finally, the simulation model reveals that the ATPS interface fluctuations in systems with magnetic NPs as a partitioned species can be controlled by the magnetic field at length scales much smaller than those probed experimentally to date.

Rational construction of a self-assembled nanoprobe for specific imaging ATP in cancer cells

Adenosine triphosphate (ATP) serves as the energy currency unit and plays a crucial role in various cellular processes. While many small molecule fluorescent probes have been successfully developed for detecting ATP, their biological applications have been limited due to the restrictions of specificity of ATP response and targeting cancer cells. This study introduces a novel self-assembled polymer fluorescent nanoprobe, RdB-DETA-HA NPs, specifically designed for the monitoring and imaging of ATP in live cancer cells. The nanoprobe integrates diethylenetriamine-linked rhodamine B as a fluorescence recognition moiety for ATP, covalently incorporated with hyaluronic acid (HA). This innovative design enhances water dispersibility, prevents dye leakage, and significantly improves cancer cell targeting via CD44 receptor-mediated endocytosis. Our results demonstrate the nanoprobe's exceptional ability to specifically target cancer cells and dynamically monitor ATP levels, marking a substantial advancement over traditional small molecule probes. The RdB-DETA-HA NPs show great promise for widespread applications in biomedical research and diagnostic imaging.

Nano- and meso-scale aggregation of poly(N-isopropylacrylamide) below the lower critical solution temperature: A wide-angle dynamic light scattering study

Poly-N-isopropylacrylamide (PNIPAm), a thermorresponsive polymer, highly soluble in water below its lower critical solution temperature (LCST), is widely used in biomedical applications like drug delivery. Being able to measure PNIPAm size and aggregation state in solution quickly, inexpensively, and accurately below the LCST is critical when stoichiometric particle or molecular ratios are required. Dynamic light scattering (DLS) is probably the most widely available, and inexpensive nanoparticle sizing technique, but there are limitations with respect to sample polydispersity. Here, we first investigated factors governing the ability of DLS to accurately measure PNIPAm size in solution at 25 °C as part of a quality study of five different molecular weight, commercially sourced PNIPAm. All samples were polydisperse and accurate particle size distribution (PSD) data was only obtained from distribution fitting, being consistent and accurate down to ∼ 0.1 wt%. In water at 1 wt%, Rh, extracted from distribution fitting: 12.4 ± 0.6 nm (55 kDa), 10.0 ± 0.22 nm (38 kDa), 6.2 ± 0.15 nm (28.5 kDa), and 9.7 ± 0.14 nm (20-25 kDa) were significantly higher than that expected for single PNIPAm chains in solution. Measurements in different buffers of varying pH (7.4-5.0) yielded similar sizes (Rh of 6-15 nm) and polydispersity indicating that these were stable aggregates. These aggregates could be broken down with Triton-X but not with sodium dodecyl sulphate, ultrasound, or by heating above the LCST and then cooling. We suggest that this nanoscale aggregation and increased polydispersity was caused a variety of factors including by solid-state aging during prolonged storage (>5 years) induced by water adsorption, and/or manufacturing processes. Stirring was found to produce larger, meso-scale (Rh > 150 nm), soluble aggregates and the rate of formation of these meso-particles was linear with stirring time (with a concomitant linear decrease in the faction of original nanoscale aggregates). Meso-particle formation was not correlated with MW, but was inversely correlated to polymer concentration suggesting that aggregation was driven by adsorption at air/liquid interfaces rather than solution phase collisions. In conclusion, PNIPAm particle size and distribution was highly dependent on multiple factors including source, storage conditions, and exposure to air-water interfaces. Standard wide angle DLS is however an effective and rapid method for identifying and quantifying PNIPAm aggregation.

Enhancing the biological characteristics of aminolysis surface-modified 3D printed nanocomposite polycaprolactone/nanohydroxyapatite scaffold via gelatin biomacromolecule immobilization: An in vitro and in vivo study

The surface characteristics of scaffolds utilized in bone tissue engineering profoundly influence subsequent cellular response. This study investigated the efficacy of applying a gelatin coat to the surface of aminolysis surface-modified scaffolds fabricated through 3D printing with a polycaprolactone/hydroxyapatite nanocomposite, employing the hot-melt extrusion FDM technique. Initially, aminolysis surface modification using hexamethylenediamine enhanced surface hydrophilicity by introducing amine functional groups. Subsequently, gelatin solutions were applied to the scaffolds, and crosslinking with EDC/NHS was performed to increase coating strength. Contact angle measurements revealed a significantly increased surface hydrophilicity post-aminolysis. Aminolysis facilitated uniform gelatin coating formation and distribution. Subsequently, crosslinking enhanced coating durability. The addition of gelatin coating resulted in a notable 20 % increase in scaffold mechanical strength and more than 50 % rise in Young's modulus and exhibited enhancement of biodegradability and bioactivity. Gelatin coated scaffolds also demonstrated improved cell viability and adhesion and over two times higher expression of OPN and ALP genes, suggesting improved biological properties. In addition, in vivo bone formation studies verified the biological enhancement of scaffolds. Utilizing an immobilized crosslinked gelatin biomacromolecule coating effectively enhanced the biological characteristics of 3D printed scaffolds and their potential applications as bone tissue engineering scaffolds.

A super soft thermoplastic biodegradable elastomer with high elasticity for arterial regeneration

Elastomers with innovative performance will provide new opportunities for solving problems in soft tissue repair, such as arterial regeneration. Herein, we present a thermoplastic biodegradable elastomer (PPS) that differs from the rigid, low-elastic traditional ones. It shows super softness (0.41 ± 0.052 MPa), high stretchability (3239 ± 357 %), and viscoelasticity similar to natural soft tissues. In addition, it also has good processability and appropriate degradability, estimated at 4-8 months for complete degradation in vivo. This excellent overall performance makes it a great support material for soft tissue repair and a powerful modifying agent for improving existing materials. For example, introducing it into poly(l-lactide) scaffolds through thermally induced phase separation can create a unique microporous structure with interconnected large pores (diameter >10 μm), demonstrating high efficiency in inducing cell infiltration. Blending it with poly(ε-caprolactone) through electrospinning can produce a composite fibrous film with significantly improved comprehensive performance, displaying artery-matched mechanical properties. Building on the above, we constructed a tri-layer tissue-engineered vascular graft for arterial regeneration, exhibiting promising remodeling outcomes in rabbits.

Advances in the degradation and recycling of polyurethanes: biodegradation strategies, MALDI applications, and environmental implications

Polyurethanes pose significant environmental challenges due to their limited recyclability and slow biodegradation. This review highlights recent advancements in polyurethanes degradation and recycling, with a particular focus on the application of Matrix-Assisted Laser Desorption/Ionization techniques. This methods have made significant progress in analyzing environmental contamination by polyurethanes, offering a detailed understanding of degradation products and polymer structures. The review discusses key advancements in biostimulation and bioaugmentation strategies that have led to notable improvements in polyurethanes degradation rates in soils, offering potential solutions for large-scale waste management. Additionally, the comparative advantages of recycling methods, such as glycolysis, aminolysis, and hydrolysis, are highlighted, focusing on their efficiency, environmental impact, and potential for industrial application. The scalability of these technologies is also considered, with potential for broad implementation in the recycling industry. Furthermore, Matrix-Assisted Laser Desorption/Ionization techniques are examined as a powerful tool for analyzing polyurethanes-based waste, with insights into optimizing sample preparation and improving detection sensitivity for large-scale applications. This review provides a comprehensive overview of current and emerging trends in polyurethanes degradation and recycling, emphasizing their industrial relevance and future prospects.

Single-molecule resolution of the conformation of polymers and dendrimers with solid-state nanopores

Polymers and dendrimers are macromolecules, possessing unique and intriguing characteristics, that are widely applied in self-assembled functional materials, green catalysis, drug delivery and sensing devices. Traditional approaches for the structural characterization of polymers and dendrimers involve DLS, GPC, NMR, IR and TG, which provide their physiochemical features and ensemble information, whereas their unimolecular conformation and dispersion also are key features allowing to understand their transporting profile in confined ionic nanochannels. This work demonstrates the nanopore approach for the determination of charged homopolymers, neutral block copolymer and dendrimers under distinct bias potentials and pH conditions. The nanopore translocation properties reveal that the dispersion and transporting of PEI is pH-dependent, and its capture rate is much lower than that of PAA. The neutral block copolymer with longest molecular chain threads through with longest blockage duration, its highest capture rate was achieved in 0.5 M KCl at pH 5 with slow diffusion and high temporal resolution. The two generations of neutral dendrimers could also translocate under bias potentials, probably due to the ions adsorption on the dendrimers and driven by Brownian force. The TEG-81 with larger molecular size translocates with longer residence time and higher blockage ratio, as expected. Both of the dendrimers exhibit a higher blockage ratio at pH 7.4 than either acidic or alkalic condition, indicating a larger stretched conformation adopted under neutral condition. This work presents the analysis of unimolecular charged and neutral polymers and dendrimers, which will be insightful in understanding the self-assembly motion and transfer of synthetic macromolecules in confined space. It also provides a good indication for deciphering the macromolecule-nanopore interplay under electrophoretic condition.

Drug-device-field integration for mitochondria-targeting dysfunction and tumor therapy by home-tailored pyroelectric nanocomposites

In spite of the hypoxia tumor microenvironment, an efficacious treatment with minimal invasiveness is highly desirable. Among common cellular organelles, mitochondria is a common target for inductive cellular apoptosis and tumor proliferation inhibition. Nevertheless, tumor hypoxic circumstances always give rise to poor therapeutic efficiency and instead lead to lesion recurrence and unsatisfactory prognosis. Herein, a home-tailored pyroelectric nanocomposites of BTO@PDA-FA-DOX-EGCG have been developed via a layer-by-layer synthesis to serve a cutting-edge tumor treatment with specific mitochondria-targeting, hypoxia-relieving, chemo-photodynamic performance and high anti-tumor efficacy. In particular, this therapeutic modality is featured as drug-device-field integration (DDFI) by combining chemo-drugs of DOX and EGCG, a commercially available medical laser and physical pyroelectric fields, which synergistically contributed to continuing ROS production and consequently cell apoptosis and tumor growth inhibition. Meanwhile, an anti-tumor mechanism of immune actuation and mitochondria dysfunction was elucidated by analyzing specific biomarkers of mitochondria complexes and MMPs, and therefore this research opened up a potential pathway for advanced tumor treatment by incorporating nanocomposites, medical devices and physical fields in a DDFI manner.

A cationic main-chain poly(carbonate-imidazolium) potent against Mycobacterium abscessus and other resistant bacteria in mice

The incidence of serious lung infections due to Mycobacterium abscessus, a worrying non-tuberculosis mycobacteria (NTM) species, is rising and has in some countries surpassed tuberculosis. NTM are ubiquitous in the environment and can cause serious lung infections in people who are immunocompromised or have pre-existing lung conditions. M. abscessus is intrinsically resistant to most antibiotics. Current treatments involve combination of three or more repurposed antibiotics with the treatment regimen lasting at least 12 months but producing unsatisfactory success rates of less than 50 %. Herein, we report an alternative strategy using a degradable polymer, specifically main-chain cationic carbonate-imidazolium-derived polymer (MCOP-1). MCOP-1 is a non-toxic agent active in a murine lung infection model. MCOP-1 also exhibits excellent efficacy against multi-drug resistant (MDR) ESKAPE bacteria. MCOP-1 damages bacterial membrane and DNA, and serial passaging does not rapidly elicit resistance. Its carbonate linkage is stable enough to allow MCOP-1 to remain intact for long enough to exert its bactericidal effect but is labile over longer time periods to degrade into non-toxic small molecules. These findings underscore the potential of degradable MCOP-1 as a promising therapeutic antimicrobial agent to address the growing incidence of recalcitrant infections due to M. abscessus and MDR ESKAPE bacteria.

A novel strategy for addressing post-surgical abdominal adhesions: Janus hydrogel

Abdominal adhesions are a frequent complication after abdominal surgery, which can cause significant pain and burden to patients. Despite various treatment options, including surgical intervention and pharmacotherapy, these often fail to consistently and effectively prevent postoperative abdominal adhesions. Janus hydrogel is famous for its asymmetric characteristics, which shows great prospects in the prevention and treatment of abdominal adhesion. This review outlines the preparation methods, mechanisms of action, and key applications of Janus hydrogel in the prevention of postoperative abdominal adhesions. Furthermore, we examine the current limitations of the Janus hydrogel anti-adhesion barrier and explore potential future directions for its development.

Biophysical Aspect of Assembly and Regulation of Nuclear Bodies Scaffolded by Architectural RNA

A growing body of evidence suggests that nuclear bodies, condensates of RNAs and proteins within the nucleus, are assembled through liquid-liquid phase separation. Some nuclear bodies, such as paraspeckles, are scaffolded by a class of RNAs known as architectural RNAs. From a materials science perspective, RNAs are categorized as polymers, which have been extensively studied in soft matter physics. While soft matter physics has the potential to provide significant insights, it is not directly applicable because transcription and other biochemical processes differentiate RNAs from other polymers studied in this field. Therefore, an interdisciplinary research fusing molecular biology and soft matter physics offers a powerful approach to studying nuclear bodies. This review introduces the biophysical insights provided by such interdisciplinary research in the assembly and regulation of nuclear bodies.

Demonstrating performance in scaled-up production and quality control of polyhydroxyalkanoates using municipal waste activated sludge

Significant progress has been made over the past decade with pilot scale polyhydroxyalkanoate (PHA) production by direct accumulation using municipal waste activated sludge (WAS). However, industrial upscaling experiences are still lacking in the research literature. In this study, a demonstration scale (4 m3) PHA production process was operated using industrially relevant equipment and compared favourably to those from parallel pilot scale (200 L) production runs. WAS grab samples from a Dutch full scale municipal wastewater treatment plant (WWTP) was used as the biomass source. Final biomass PHA contents and production yields, that are critical for technology viability, were statistically the same between the experiments conducted at pilot scale (0.41 ± 0.02 gPHA/gVSS and 0.42 ± 0.02 gCOD/gCOD) and demonstration scale (0.45 ± 0.05 gPHA/gVSS and 0.39 ± 0.07 gCOD/gCOD). The results furthermore aligned with previous 1 m3 piloting experiences and five year old historical data that similarly used WAS sourced from the same WWTP. Scalability for the technology and a robustness of the applied PHA production methods using WAS were demonstrated. Temperature and foaming control were identified to be critical to upscaled process engineering and design towards successful industrial implementations. The results of the present study, combined with previously produced PHAs and those historical data, support that feedstock quality predictably determines both the average PHA co-monomer content, as well as the blend distribution. PHA solvent extraction from WAS is inherently a blending process. Extraction homogeneously mixes polymer contributions from collectively stored granules from all species of microorganisms in the biomass. Dried PHA-rich biomass batches can be stockpiled and batches can be blended in extraction processes for both recovery and formulation to reach consistent polymer qualities across production batches. More centralized extraction facilities are therefore anticipated to offer economic benefits due to scale and greater opportunities for product quality specification and control. Research findings are presented herein of the production scale comparative study along with practical perspectives of technological readiness for realizing WAS based industrial scale PHA production, quality control, and the supply chains that will be necessary for successful commercial implementation.

Recombinant alginate lyases and mannitol dehydrogenase enhance hydrolysis of macroalgal carbohydrates

Brown macroalgae are a promising source for bioethanol production, primarily due to their high carbohydrate, low lignin and high moisture content. Bioconversion of macroalgae to ethanol requires a yeast, such as Saccharomyces cerevisiae, that can hydrolyse the macroalgal carbohydrates, namely laminarin, mannitol and alginate. In this study, the mannitol dehydrogenase (MDH) genes from Aspergillus fumigatus (AfMDH) and Talaromyces islandicus (TiMDH), and the alginate lyase (AL) genes from Sphingomonas sp. (SpxAL and SpeAL) and Talaromyces emersonii (TeeAL) were expressed in the laboratory strain, S. cerevisiae Y294. Co-cultures of a laminarinase-producing yeast, Y294[Relam1/Tvlam1] and yeasts expressing mannitol dehydrogenases and alginate lyases were evaluated for the consolidated bioprocessing of the major carbohydrates in brown macroalgae. Laminarin and mannitol were targeted for ethanol production, while alginate was depolymerised to expose mannitol. A co-culture of S. cerevisiae Y294[Relam1/Tvlam1], [AfMDH] and [TeeAL/SpxAL] strains produced 10.30 g/L ethanol from Ecklonia maxima, representing a 98 % carbon conversion (based on the laminarin and mannitol content). A strain expressing both endo- and exo-alginate lyase improved the ethanol yield by 42.28 % compared to strains expressing only laminarinase- and mannitol dehydrogenase. Scanning electron microscopy further revealed that co-cultures containing laminarinase, MDH, and AL enzymes promoted significant physical degradation and increased porosity in macroalgal substrates, suggesting enhanced alginate hydrolysis and improved enzyme accessibility. This is the first report on the simultaneous hydrolysis of mannitol, alginate and laminarin with recombinant enzymes during macroalgal fermentation. The results demonstrate significant progress towards exploiting brown macroalgae for bioconversion to ethanol and high-value products.

An adhesive, antibacterial hydrogel wound dressing fabricated by dopamine-grafted oxidized sodium alginate and methacrylated carboxymethyl chitosan incorporated with Cu(II) complex

Effective wound dressings play an important role in preventing infections and promoting wound healing. Most polysaccharide-based hydrogel dressings have the drawbacks of weak tissue adhesion and poor antibacterial properties. Herein, a multifunctional dopamine-grafted oxidized sodium alginate-methacrylated carboxymethyl chitosan/gallic acid‑copper(II) complex (OD-CM/GA-CuIIUV) hydrogel was fabricated through Schiff base bonds and photo-crosslinked polymerization between dopamine-grafted oxidized sodium alginate (OSA-DA) and methacrylated carboxymethyl chitosan (CMC-MA), with the integration of gallic acid‑copper(II) complexes (GA-CuII). The double cross-linked network and mussel-inspired adhesion mechanism endowed the hydrogel with attractive physicochemical properties, including excellent self-healing properties, pH-responsive biodegradability, robust toughness, and a maximum adhesion strength of 15.06 kPa. Moreover, the composite hydrogel exhibited an antibacterial ratio of > 99 % against Escherichia coli and Staphylococcus aureus, as well as good antioxidant activity. The MTT assay showed that the cell viability of the composite hydrogel reached > 85 %. The in vivo full-thickness skin defect healing assays in rats demonstrated that the composite hydrogel remarkably accelerated wound repair by attenuating the inflammatory response and promoting epithelial tissue remodeling. Therefore, this novel multifunctional hydrogel has potential applications in biomedical wound dressing.

Poly(ionic liquid)-regulated green one-pot synthesis of Au@Pt porous nanospheres for the smart detection of acid phosphatase and organophosphorus inhibitor

Here, a green poly(ionic liquid)-regulated one-pot method is developed for the synthesis of Au@Pt core-shell nanospheres (PNSs) under mild reaction conditions in water. It is found that the poly(ionic liquid) poly[1-methyl-3-butyl (3-hydroxy) imidazole] chloride (PIL-Cl) is very vital to guide the construction of Au@Pt PNSs. The as-obtained Au@Pt-1 PNSs have perfect spherical outlines, porous core-shell structures and large specific surface area by which they exhibit excellent peroxidase-like activity in acidic media and can be used to develop a simple and reliable colorimetric sensing platform. It is shown that the colorimetric sensing platform constructed with Au@Pt-1 PNSs nanozyme can effectively evaluate ACP activity, achieving a wide linear detection range of 0.1-3.0 U/L and having a low limit of detection (LOD) of 0.047 U/L (S/N = 3). Based on the cascade reaction, the Au@Pt-1 PNSs nanozyme and ACP are integrated to develop a biosensor, which can detect organophosphate inhibitor of malathion with a wide linear detection range of 5-80 nM and low LOD of 1.96 nM (S/N = 3). More importantly, this detection method is also practically applied to detect both ACP activity in fetal bovine serum and malathion concentration in cucumber juice with satisfied results. This work presents a simple and green feature for the synthesis of nanozyme with high performance and establishes a biosensing platform based on Au@Pt-1 PNSs nanozyme to effectively monitor the ACP activity and the concentration of its organophosphate inhibitor malathion with high sensitivity, anti-interference capability and good recovery capability.

Tannic acid as a multifunctional additive in polysaccharide and protein-based films for enhanced food preservation: A comprehensive review

Fossil-based polymers continue to dominate the market for single-use food packaging, despite increasing concerns about their sustainability. In response, natural and renewable polymers, such as proteins and polysaccharides, are gaining attention as potential alternatives due to their biodegradability and biocompatibility. However, their broader adoption is hindered by the need to improve their mechanical, barrier, and thermal properties. Tannic acid (TA) has emerged as a particularly effective additive for biopolymer-based films, offering strong antioxidant and antimicrobial properties. It also enhances mechanical and barrier characteristics through physical and/or covalent crosslinking. As a result, TA shows great potential as an additive for bioplastics, improving food packaging performance and extending product shelf life, while benefiting both the environment and the food industry. Despite the promising applications of TA, comprehensive reviews that focus on recent developments in its performance and bioactive properties remain limited. This review aims to highlight the effectiveness of TA as both an active ingredient and a crosslinking agent in various biopolymer films, offering valuable insights into its role in sustainable food packaging solutions by critically examining the latest advancements.

Cationic conjugated polymers with tunable hydrophobicity for efficient treatment of multidrug-resistant wound biofilm infections

Biofilm-associated infections arising from antibiotic-resistant bacteria pose a critical challenge to global health. We report the generation of a library of cationic conjugated poly(phenylene ethynylene) (PPE) polymers featuring trimethylammonium terminated sidechains with tunable hydrophobicity. Screening of the library identified an amphiphilic polymer with a C11 hydrophobic spacer as the polymer with the highest antimicrobial efficacy against biofilms in the dark with excellent selectivity. These polymers are highly fluorescent, allowing label-free monitoring of polymer-bacteria/biofilm interactions. The amphiphilic conjugated polymer penetrated the biofilm matrix in vitro and eradicated resident bacteria through membrane disruption. This C11 polymer was likewise effective in an in vivo murine model of antibiotic-resistant wound biofilm infections, clearing >99.9 % of biofilm colonies and efficient alleviation of biofilm-associated inflammation. The results demonstrate the therapeutic potential of the fluorescent conjugated polymer platform as a multi-modal antimicrobial and imaging tool, surpassing conventional antimicrobial strategies against resilient biofilm infection.

Progress of 0D Biomass-Derived Porous Carbon Materials Produced by Hydrothermal Assisted Synthesis for Advanced Supercapacitors

Supercapacitors are garnering considerable interest owing to their high-power density, rapid charge-discharge capability, and long cycle life. Among the various materials explored, biomass-derived carbon nanomaterials stands out as a sustainable and cost-effective choice, thanks to its natural abundance and eco-friendly characteristics. This review delineates recent advances in the synthesis of zero-dimensional (0D) carbon nanomateirlas from various biomass precursors via hydrothermal assisted synthesis. It offers a comprehensive discussion on the factors affecting the synthesis of 0D carbon nanomaterials, including precursor type, concentration, reaction temperature, and time. Furthermore, the review underscores the impact of different activation methods on the morphology and electrochemical performance of 0D carbon nanomaterials. Finally, we outline the challenges and future prospects of utilizing biomass-derived carbon nanomaterials in supercapacitor applications, emphasizing the importance of optimizing synthesis parameters to attain the desired material properties.

Antibacterial and osteogenic gain strategy on titanium surfaces for preventing implant-related infections

Infection and insufficient osseointegration are the primary factors leading to the failure of titanium-based implants. Surface coating modifications that combine both antibacterial and osteogenic properties are commonly employed strategies. However, the challenge of achieving rapid antibacterial action and consistent osteogenesis with these coatings remains unresolved. In this study, a functional composite coating (PDA/PPy@Cu/Dex) was prepared on titanium surfaces using layer-by-layer self-assembly and electrochemical deposition techniques. The hydroxyl groups grafted by polydopamine's (PDA) self-polymerization and the enhanced conductivity and uniform electric field distribution provided by polypyrrole (PPy) allowed for the even dispersion of copper nanoparticles and dexamethasone (Dex) on the titanium surface. This synergistically coupled the photothermal ion antibacterial properties of copper nanoparticles with the osteogenic promotion of dexamethasone. In vitro antibacterial experiments revealed that the heat generated by photothermal effects and reactive oxygen species enhanced the antibacterial activity of copper ions, reducing the antibacterial time to six h and achieving antibacterial enhancement. In vitro cell experiments showed that the long-term slow release of copper ions and dexamethasone enhanced the osteogenic differentiation of stem cells, thereby achieving osteogenic benefits. Moreover, in vivo toxicity experiments demonstrated that the composite coating had no adverse effects on normal tissues. Therefore, the antibacterial and osteogenic enhancement strategy for titanium surfaces presented in this study offers a new potential approach for preventing implant-associated infections.

Ultrasound stimulated piezoelectric antibacterial silk composite films guiding differentiation of mesenchymal stem cells

Smart materials for tissue engineering have been in extensive use for few decades now. This work delves into the exploration of ultrasound-stimulated piezoelectric and antibacterial silk-based composite films as a pioneering strategy to guide the differentiation of human mesenchymal stem cells into osteogenic lineage without the application of any exogenous growth factors. The study evaluates the biocompatibility and antibacterial attributes of these films, which incorporates Barium Titanate nanoparticles (BTNPs) along with Zinc Oxide nanoparticles for obtaining high piezo modulated stimuli response and antibacterial properties. Further, to enhance the piezoelectric capability, a novel calcium doped Barium Titanate (BCTs) nanoparticles were synthesized and incorporated in silk based films with ZnO. The choice of using calcium as a doping material allows to increase its piezoelectric potential and retain its biocompatibility. The results reveal that, under the influence of ultrasound stimulation, these composite films respond to mechanical cues like low frequency ultrasound stimulations to facilitate lineage-specific differentiation of the seeded human mesenchymal stem cells. Ultrasound stimulations being wireless avoid complicated wired electric circuits and are also known to activate calcium channels in the cells which aids osteogenesis. Significantly, our findings exhibit the profound potential of these films to exploit the piezoelectric properties of BCTs, effectively enhancing the differentiation trajectories of stem cells. Furthermore, their demonstrated antibacterial capacities underscore their pivotal role in infection prevention, an important facet in the domains of tissue engineering and medical implantation. This study strongly suggests the utility of ultrasound-stimulated silk-based composite films in advancing the frontiers of regenerative medicine and tissue engineering.