Macromolecular Rapid Communications最新文献

Catechol grafted macromolecules have attributes that overlap what's needed within non-toxic bioadhesives. However, decades of research have failed to make commercial progress as a general tissue adhesive. The major impediments include reliance on harmful crosslinking additives, long-term shelf-stability, and variability in preparation (e.g. two component mixing). This can arguably be assigned to the over-reliance on just one catechol crosslinker based on L-dopamine. Herein, we evaluate catechol scaffolds and oxidation processes that side-step these limitations and provide one-component (1C) bioadhesive designs. These 1C designs hypothesize activation via surface contact and oxygen exposure. The branched polyethylenimine (PEI) dendrimer serves as a model macromolecule, easily grafted via Schiff-base click chemistry. One of the optimized formulations, PEI-(5-OMe-3,4-DBA)₂₀, in which 20% of the primary amine groups of PEI are grafted with 5-methoxy-3,4-dihydroxybenzaldehyde (5-OMe-3,4-DBA) through Schiff-base linkages, initiates crosslinking immediately after air/O₂ exposure, but remains stable in anaerobic environments. Structural evaluation confirms PEI-(5-OMe-3,4-DBA)₂₀ undergoes spontaneous conversion to quinones, supported by aromatic CH integration (¹H-NMR) and first order decay of 5-OMe catechol Schiff-base (UV–vis). Gelation time occurs in 〈 1 min with shear strengths of 26 kPa on wetted collagen substrates.

α-Ethylidene-δ-vinyl-δ-valerolactone (EVL), a trifunctional monomer derived from CO₂ and 1,3-butadiene, provides a versatile platform for the construction of functional polyesters. A furan-functionalized monomer (EVL-FML), synthesized via thiol–Michael addition of EVL, exhibits a low ceiling temperature (T_c = −102.4°C) that precludes its homopolymerization. To overcome this thermodynamic limitation, EVL-FML is copolymerized with the Michael adduct of EVL and 1-propanethiol (EVL-SPr), which possesses a higher T_c of −2.4°C. Catalyzed by 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD), the ring-opening copolymerization (ROCP) yields polyesters bearing furan groups (PF-x, 0–50 mol%) with number-average molecular weights up to 13.1 kg mol⁻¹, and narrow distributions (Р< 1.2). Kinetic studies reveal that the ROCP follows pseudo-first-order kinetics, with a reaction order of 0.37 with respect to TBD. The reactivity ratios are determined to be r_EVL-SPr = 0.94 and r_EVL-FML = 0.75. Subsequently, maleimide-functionalized (13–59 mol%) polyesters (PM-y) are prepared via post-polymerization modification of PEVL-SPr. Thermally reversible covalent adaptable networks (CANs) are constructed through the Diels–Alder reaction between PF-x and PM-y, exhibiting cross-link densities ranging from 110 to 572 mol m⁻³ and tensile strengths between 0.42 and 12.45 MPa. These networks demonstrate excellent self-healing, reprocessability, and inherent degradability, offering a promising pathway toward sustainable functional materials.

To validate moderate chemical aggregation of flame-retardant groups as an effective strategy for obtaining advanced flame-retardant molecules, moderate-aggregated linear oligomer B-PDHQ (trimer-dominant) and high-aggregated crosslinked macromolecule C-PDHQ were synthesized via the polymerization between the 10-(2,5-Dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ) monomer and formaldehyde. By propagating linear polymerization aggregation of phenolated phosphaphenanthrene (PDOPO) groups, the moderate-aggregated B-PDHQ exhibits outstanding superiority in combustibility suppression efficiency and toughness enhancement effectiveness of epoxy thermoset (EP), compared with the highly aggregated C-PDHQ and non-aggregated monomer DOPO-HQ. Especially, 3%B-PDHQ/EP passed UL94 V-0 rating, 3%DOPO-HQ/EP only passed UL94 V-2 rating, while 3%C-PDHQ/EP failed to pass any rating of UL94 vertical burning test. Furthermore, moderate-aggregated B-PDHQ also showed leading efficiency in the limited oxygen index, combustion heat inhibition, smoke emission reduction, and char formation enhancement of EP. The behavior of linear oligomer B-PDHQ that triggers the flame-retardant groups aggregation effect was revealed from the condensed-phased char-forming behavior, char layer morphology investigation, and the gas-phased thermal decomposition volatile tracing. In addition, the moderate polymerization aggregation of PDOPO groups in linear oligomer B-PDHQ still enable EP matrix with a higher glass transition temperature and impact toughness. The superiority of moderate-aggregated B-PDHQ provides a practical and efficient route for designing and manufacturing high-performance reactive flame-retardant molecules.

While immunotherapy has revolutionized cancer treatment, its clinical efficacy is still constrained by tumor heterogeneity, acquired drug resistance, and the immunosuppressive tumor microenvironment. Traditional apoptosis-driven cancer therapeutic strategies are often inefficient and immunologically silent. In contrast, non-apoptotic programmed cell death (PCD) pathways (ferroptosis, pyroptosis, necroptosis, and cuproptosis) offer high immunogenicity and the ability to bypass resistance mechanisms, yet their clinical application is limited by poor tumor specificity, off-target toxicity, and delivery inefficiency. Peptide self‑assembly technology has emerged as a powerful platform to address these challenges, enabling enzyme‑responsive morphological transformation, multivalent target binding, subcellular localization, multifunctional co‑assembly, and artificial enzyme mimicry for precise PCD induction. Despite significant progress, a systematic classification of how peptide assemblies trigger distinct PCD pathways is still lacking. This review categorizes peptide self‑assembly‑induced tumor cell death into five major themes, including ferroptosis, pyroptosis, necroptosis, cuproptosis, and combined death. By summarizing the design principles, key evidence, and anti‑tumor outcomes, this review highlights the unique advantages of peptide self‑assembly. It provides a theoretical foundation for developing peptide‑based precision cancer therapies and aims to guide future research toward clinical translation and personalized treatment.