Thiol-ene Click Chemistry Research Articles

Thiol-ene click chemistry: Enabling 3D printing of natural-based inks for biomedical applications

Thiol-ene click chemistry: Enabling 3D printing of natural-based inks for biomedical applications

Controlled Synthesis of Bioderived Poly(limonene carbonate)-Oligolysine Hybrid Macromolecules.

A straightforward and stepwise functionalization of poly(limonene carbonate) (PLC) was achieved through the use of thiol-ene click chemistry introducing primary amine groups. These amines are initiating points for N-carboxy anhydride (NCA) ring-opening polymerization (ROP) reactions, allowing us to modify the PLC backbone with oligolysine fragments, thereby creating a polymer brush type macromolecule. These newly prepared biohybrid structures show a clear hydrophilic behavior as evident from their physical behavior and contact angle measurements.

Cytocompatible Hydrogels with Tunable Mechanical Strength and Adjustable Swelling Properties through Photo-Cross-Linking of Poly(vinylphosphonates).

Herein, the synthesis, characterization, and application of a novel synthetic hydrogel based on the photoinitiated cross-linking of poly(vinylphosphonates) is presented. First, statistical copolymers with adjustable ratios of the monomers diallyl vinylphosphonate (DAlVP) and diethyl vinylphosphonate (DEVP), as well as different molecular weights, were obtained via rare earth metal-mediated group-transfer polymerization (REM-GTP) while maintaining narrow polydispersities. The copolymers were cross-linked by applying photoinitiated thiol-ene click chemistry (λ = 365 nm). The network formation was monitored via oscillatory rheology coupled with UV-irradiation, revealing the high spatiotemporal control of the reaction. Moreover, the equilibrium storage moduli of poly(vinylphosphonate)-based hydrogels increased with a growing number of DAlVP units and upon application of a different cross-linker, which was additionally confirmed by nanoindentation experiments. In contrast, the water uptake of hydrogels decreased with higher DAlVP amounts in the corresponding hydrogels due to lower chain mobility and an overall increase in the hydrophobicity of the samples. Upon successful functionalization of P(DEVP-stat-DAlVP) copolymers with sodium 3-mercaptopropane-1-sulfonate, as indicated via 1H DOSY NMR, the respective cross-linked materials displayed a remarkable increase in the water uptake; thus, presenting highly hydrophilic gels with an apparent interplay between water uptake, cross-linking density, and functionalization degree. Finally, the purified hydrogels showed cytocompatibility and enabled cell adhesion of human umbilical artery smooth muscle cells (HUASMCs) after direct seeding. The materials further allowed the adhesion and growth of an endothelial layer, triggered no pro-inflammatory response as evidenced by cytokine release of M0 macrophages, and exhibited antibacterial properties toward S. aureus and E. coli.

Self-cascade ROS-trapping bioreaction system reverses stem cell oxidative stress fate for osteogenesis

eactive oxygen species (ROS) scavenging is essential for periodontal regeneration. However, the dynamic change of the applied materials within the ROS-rich environment and the residual oxidation products in the host highly impact periodontal regeneration. This study successfully constructs a bioreaction system via thiol-ene click chemistry, leveraging the high affinity of glutathione (GSH) for ROS to attract excess ROS to the crosslinking points. Two minutes after hydrogen peroxide (H2O2) treatment, the ROS level in the G8-0 hydrogel acutely decreases, reaching a 4.4% reduction within 10minutes, confirming the ROS-trapping efficacy. Through a ‘bait switch-on’ mechanism, hexagonal boron nitride (hBN) takes over the captured ROS and the oxidation products of pectin further drive the reduction reaction, ultimately restoring the extracellular environment. The self-cascade products, oxidized hBN, reshape the intracellular oxidative stress (OS) environment, achieving a synergistic extra- and intra-cellular treatment. The significantly high reduced to oxidized glutathione (GSH/GSSG) ratio in G8-10 hydrogel (~80%) illustrates a reversal of oxidative stress in bone marrow stem cells (BMSCs). On a molecular level, the bioreaction system inhibits the NF-κB pathway, promoting the expression of key antioxidant genes (Nqo1 and Nrf2) and osteogenic molecules (ALP and OCN), thereby reversing the detrimental effects of OS on BMSCs. In vivo application demonstrated the system’s strong redox-balancing and osteogenic capabilities in the periodontal inflammation environment. This novel antioxidant bioreaction system, characterized by self-cascade ROS-trapping and product utilization, offers innovative treatment strategies for tissue regeneration under conditions of excessive OS.

Preparation and evaluation of a pyridine sulfonate betaine-based zwitterionic stationary phase for hydrophilic interaction chromatography

A zwitterionic stationary phase comprising pyridinium cations and sulfonate anions was successfully developed through thiol-ene click chemistry. Using seven polar small molecules as probes, the zwitterionic stationary phase showed high separation selectivity and excellent column efficiency (35,200–54,800 plates/m) compared with two commercial columns. The influence of water proportion, salt concentration, and pH in the mobile phase, and column temperature, on the retention of six polar compounds was examined. The retention mechanism was explored by three hydrophilic retention models, Tanaka test and linear solvation energy relationship analysis. For the analysis of sample dairy products (milk powder, milk, and yogurt), the stationary phase was operated in hydrophilic interaction chromatography mode without the addition of buffer salts, facilitating rapid and efficient detection and quantification of melamine. The LOD and LOQ are 0.04 mg⋅g−1 and 0.13 mg⋅g−1, respectively, and the recovery rate is 90.3 − 102.8 %. The zwitterionic stationary phase has the advantages of simple preparation, good method reproducibility, good selectivity and high precision.

Controlled Transdermal Delivery of Dexamethasone for Pain Management via Photochemically 3D-Printed Bioresorbable Microneedle Arrays.

Microneedle array patches (MAPs) are extensively studied for transdermal drug delivery. Additive manufacturing enables precise control over MAP customization and rapid fabrication. However, the scope of 3D-printable, bioresorbable materials is limited. Dexamethasone (DXM) is widely used to manage inflammation and pain, but its application is limited by systemic side effects. Thus, it is crucial to achieve high local drug concentrations while maintaining low serum levels. Here, poly(propylene fumarate-co-propylene succinate) oligomers are fabricated into DXM-loaded, bioresorbable MAPs via continuous liquid interface production 3D printing. Thiol-ene click chemistry yields MAPs with tailorable mechanical and degradation properties. DXM-loaded MAPs exhibit controlled elution of drug in vitro. Transdermal application of DXM-loaded MAPs in a murine tibial fracture model leads to substantial relief of postoperative pain. Pharmacokinetic analysis shows that MAP administration is able to control pain at a significantly lower dose than intravenous administration. This work expands the material properties of 3D-printed poly(propylene fumarate-co-propylene succinate) copolyesters and their use in drug delivery applications.

Effective Immobilization of Novel Antimicrobial Peptides via Conjugation onto Activated Silicon Catheter Surfaces.

Antibiotic-resistant microorganisms have become a serious threat to public health, resulting in hospital infections, the majority of which are caused by commonly used urinary tract catheters. Strategies for preventing bacterial adhesion to the catheters' surfaces have been potentially shown as effective methods, such as coating thesurface with antimicrobial biomolecules. Here, novel antimicrobial peptides (AMPs) were designed as potential biomolecules to prevent antibiotic-resistant bacteria from binding to catheter surfaces. Thiolated AMPs were synthesized using solid-phase peptide synthesis (SPPS), and prep-HPLC was used to obtain AMPs with purity greater than 90%. On the other side, the silicone catheter surface was activated by UV/ozone treatment, followed by functionalization with allyl moieties for conjugation to the free thiol group of cystein in AMPs using thiol-ene click chemistry. Peptide-immobilized surfaces were found to become more resistant to bacterial adhesion while remaining biocompatible with mammalian cells. The presence and site of conjugation of peptide molecules were investigated by immobilizing them to catheter surfaces from both ends (C-Pep and Pep-C). It was clearly demonstrated that AMPs conjugated to the surface via theirN terminus have a higher antimicrobial activity. This strategy stands out for its effective conjugation of AMPs to silicone-based implant surfaces for the elimination of bacterial infections.

A Facile Strategy for Constructing High-Performance Polymer Electrolytes via Anion Modification and Click Chemistry for Rechargeable Magnesium Batteries.

Polymer electrolytes play a crucial role in advancing rechargeable magnesium batteries (RMBs) owing to their exceptional characteristics, including high flexibility, superior interface compatibility, broad electrochemical stability window, and enhanced safety features. Despite these advantages, research in this domain remains nascent, plagued by single preparation approaches and challenges associated with the compatibility between polymer electrolytes and Mg metal anode. In this study, we present a novel synthesis strategy to fabricate a glycerol α,α'-diallyl ether-3,6-dioxa-1,8-octanedithiol-based composite gel polymer electrolyte supported by glass fiber substrate (GDT@GF CGPE) through anion modification and thiol-ene click chemistry polymerization. The developed route exhibits novelty and high efficiency, leading to the production of GDT@GF CGPEs featuring exceptional mechanical properties, heightened ionic conductivity, elevated Mg2+ transference number, and commendable compatibility with Mg anode. The assembled modified Mo6S8||GDT@GF||Mg cells exhibit outstanding performance across a wide temperature range and address critical safety concerns, showcasing the potential for applications under extreme conditions. Our innovative preparation strategy offers a promising avenue for the advancement of polymer electrolytes in high-performance rechargeable magnesium batteries, while also opens up possibilities for future large-scale applications and the development of flexible electronic devices.

Construction of Iron-Scavenging Hydrogel via Thiol-Ene Click Chemistry for Antibiotic-Free Treatment of Bacterial Wound Infection.

Bacteria, especially drug-resistant strains, can quickly cause wound infections, leading to delayed healing and fatal risk in clinics. With the growing need for alternative antibacterial approaches that rely less on antibiotics or eliminate their use altogether, a novel antibacterial hydrogel named Ovtgel is developed. Ovtgel is formulated by chemically crosslinking thiol-modified ovotransferrin (Ovt), a member of the transferrin family found in egg white, with olefin-modified agarose through thiol-ene click chemistry. Ovt is designed to sequester ferric ions essential for bacterial survival and protect wound tissues from damages caused by the reactive oxygen species (ROS) generated in Fenton reactions. Experimental data have shown that Ovtgel significantly enhances wound healing by inhibiting bacterial growth and shielding tissues from ROS-induced harms. Unlike traditional antibiotics, Ovtgel targets essential trace elements required for bacterial survival in the host environment, preventing the development of drug resistance in pathogenic bacteria. Ovtgel exhibits excellent biocompatibility due to the homology of Ovt to mammalian transferrin. This hydrogel has the potential to serve as an effective antibiotic-free solution for combating bacterial infections.

Antibacterial Hydrogel Adhesives Based on Bifunctional Telechelic Dendritic-Linear-Dendritic Block Copolymers.

Antibiotic-resistant pathogens have been declared by the WHO as one of the major public health threats facing humanity. For that reason, there is an urgent need for materials with inherent antibacterial activity able to replace the use of antibiotics, and in this context, hydrogels have emerged as a promising strategy. Herein, we introduce the next generation of cationic hydrogels with antibacterial activity and high versatility that can be cured on demand in less than 20 s using thiol-ene click chemistry (TEC) in aqueous conditions. The approach capitalizes on a two-component system: (i) telechelic polyester-based dendritic-linear-dendritic (DLDs) block copolymers of different generations heterofunctionalized with allyl and ammonium groups, as well as (ii) polyethylene glycol (PEG) cross-linkers functionalized with thiol groups. These hydrogels resulted in highly tunable materials where the antibacterial performance can be adjusted by modifying the cross-linking density. Off-stoichiometric hydrogels showed narrow antibacterial activity directed toward Gram-negative bacteria. The presence of pending allyls opens up many possibilities for functionalization with biologically interesting molecules. As a proof-of-concept, hydrophilic cysteamine hydrochloride as well as N-hexyl-4-mercaptobutanamide, as an example of a thiol with a hydrophobic alkyl chain, generated three-component networks. In the case of cysteamine derivatives, a broader antibacterial activity was noted than the two-component networks, inhibiting the growth of Gram-positive bacteria. Additionally, these systems presented high versatility, with storage modulus values ranging from 270 to 7024 Pa and different stability profiles ranging from 1 to 56 days in swelling experiments. Good biocompatibility toward skin cells as well as strong adhesion to multiple surfaces place these hydrogels as interesting alternatives to conventional antibiotics.

Chitosan films synthesized via thiol-ene click chemistry: Toward safe and versatile platforms for packaging, cosmetics and biomedical applications

The first synthesis of chitosan-based films using bio-based reticulating agents via Thiol-Michael addition click reaction was described, along with their successful application in packaging, cosmetics, and biomedical fields. The impact of chitosan (CS) concentration and the type of synthesized bio-sourced biacids (GD) and triacids (GT and TT) on the physicochemical properties of these films were assessed. Films prepared with dibasic and tribasic acids (4%-CS) demonstrated superior mechanical properties and lower solubility compared to those containing 2% CS. The incorporation of the bio-sourced GD, GT, and TT acids led to a reduction of 53%, 60% and 60.4%, respectively, in the water vapor permeability (WVP) of 4% CS-based films compared to the control film. Remarkably, CS-TT-4% films exhibited the highest mechanical strength (TS), elongation at break (%E), elasticity, water vapor, and light barrier properties. Cytotoxicity tests performed on the NIH 3T3 fibroblast cell line showed that CS-GD-4% films exhibited the highest compatibility. The efficiency of these films as drug carriers was tested with challenging anticancer and cosmetic molecules, particularly etoposide (ETP) caffeine (Caf), showing very high drug loading with a progressive release of less than 20% after 72h of incubation. Moreover, ex-vivo permeation studies in rat skin revealed that the percutaneous absorption of Caf is significantly increased by a factor of 5.5 compared to that of CS-GD-4%-Caf films with no significant histological alterations of skin layers. Altogether, this work evidences the most suitable casting solvent for developing safe chitosan films, promising their potential applications in the cosmetic and biomedical fields.

Synthesis of novel bioadhesive hydrogels via facile Thiol-Ene click chemistry for wound healing applications

Development of outstanding, cost-effective and elastic hydrogels as bioadhesive using Thiol-Ene click chemistry was verified. The visible light photocrosslinkable hydrogels composed of methacrylated chitosan/2,2′-(Ethylenedioxy) diethanethiol formed in presence of eosin-Y photoinitiator. Such hydrogels hold great promise for wound healing applications due to their tunable properties. Main components of hydrogels were extensively characterized using spectroscopic techniques for chemical analysis, thermal analysis, and topologic nanostructure. Various optimization conditions for best gelation time were investigated. Mechanical properties of tensile strength and elongation at break (%) were verified for best wound healing applications. Optimum hydrogel was subjected to for cytotoxicity and microbial suppression evaluation and in-vivo wound healing test for efficient wound healing evaluations. Our results demonstrate the potential use of injectable hydrogels as valuable bioadhesives in bioengineering and biomedical applications, particularly in wound closure and patches.

Architectural differences in photopolymerized PEG-based thiol-acrylate hydrogels enable enhanced mechanical properties and 3D printability

Hydrogels have been widely investigated for applications in the human body due to their tunability and biocompatibility. Nevertheless, their application is still limited by their relatively low mechanical strength relative to load-bearing tissue scaffolds like articular cartilage. In this work, we synthesized hydrogels by combining linear poly(ethylene glycol) dimethacrylate (PEGDMA) with a 3-arm-PEG end-functionalized with thiol. We demonstrate that the combination of thiol-ene click chemistry with a multifunctional crosslinker reduces the crosslink and entanglement density in comparison with the otherwise statistically crosslinked/polymerized PEGDMA, whereby the only viable mode of gelation is through radical propagation or termination at the double bond. The corresponding minimization of topological heterogeneities that arises during thiol-ene crosslinking results in hydrogels with compressive strength in the range of tens of MPa. The molar mass of the linear PEGDMA precursor is readily tunable, unlocking access to a wider range of mechanical properties. We employed photo-mediated crosslinking protocol, which is amenable to advanced processing technologies such as light-based 3D printing techniques. Such advanced fabrication processes offer high precision and control during the generation of customizable macroscopic objects. Simple prototypes were generated using digital light processing (DLP) equipment. We demonstrate that integrating a simple co-macromonomer into a widely employed hydrogel platform can unlock new mechanical regimes and mitigate the inherent brittleness associated with these materials. The simplicity of this approach, coupled with its easy tunability and adaptability to light-based techniques, holds promise for broadening hydrogel applications in tissue engineering. Our findings contribute to advancing materials and methodologies, facilitating enhanced design and fabrication of functional constructs.

Sustainable, transparent, strong toughness, UV resistance, and anti-corrosion properties of cashew shell oil-based waterborne polyurethane network derived from phloretin and sorbitan monooleate-based siloxane

The increasingly severe energy shortage and growing environmental problems have accelerated the rapid development of sustainable polymer materials. Hereon, a novel method was proposed for the synthesis of cashew nut shell oil-based waterborne polyurethane (WPUs), which exhibited excellent toughness, transparency, water resistance, UV resistance and corrosion resistance. Specifically, the sorbitan monooleate-based siloxane (MSP) was prepared via a thiol-ene click chemistry reaction. Subsequently, the plant-based phloretin (PRT) and MSP were introduced as polyols into the skeleton of WPUs through the molecular structure design strategy. Series of high bio-based content (91 %) WPUs networks were obtained via pre-polymerization and self-emulsification methods. The properties of their dispersions and films were thoroughly investigated, and it was found that the addition of MSP and PRT enhanced the overall performance of WPUs film. For instance, there was a significant increase in Tg. Additionally, they exhibited a maximum tensile strength of 31.5 MPa and a maximum toughness of 53 MJ/m3, which were the most outstanding among all reported plant oil-based WPU systems so far, indicating excellent tear resistance. Interestingly, the water absorption rate of PSWPU-40 was reduced to 7.1 %, suggesting good water resistance, which resolved the contradiction between the mechanical properties and water resistance of the current plant oil-based WPU systems. The PSPWU films exhibited promising application prospects, exemplified by its ability to effectively shield the entire UV range. Furthermore, its coating demonstrated outstanding anti-corrosion properties with a maximum anticorrosion efficiency of 97.1 %. It could be attributed to the synergistic effect of a self-crosslinking structure, higher crosslinking density, a tighter network structure, and stronger intermolecular forces (H-bond). This work provided a meaningful guide for the application and development of high-performance bio-based WPU functional coatings.

Cysteine-based antifouling superhydrophilic membranes prepared via facile thiol-ene click chemistry for efficient oil-water separation

Superhydrophilic membranes with underwater superoleophobicity for oil-water separation have been attracted widely attention. Nevertheless, oil contamination of such membranes represents a pressing challenge in this field. Superhydrophilic/underwater superoleophobic membranes with surface zwitterionic moieties are proved to show excellent antifouling properties; however, such zwitterionic surface modifiers adopted previously usually face the problem of cumbersome synthesis relying on expensive reagents and complicated procedures, accompanied with poor acid/alkali resistance due to the unstable linkers, restricting their practical applications. Herein, we describe an alternative strategy for fabricating antifouling superhydrophilic/underwater superoleophobic membranes from a natural amino acid. Sand particle-based sintered glass membranes were firstly coated with silicone nanofilaments using vinyltrichlorosilane as a precursor through chemical vapor deposition; and then the surfaces of silicone nanofilaments were further functionalized with cysteine via thiol-ene click chemistry. The resulting membranes exhibited high separation flux and efficiency for gravity-driven separation of various oil-water mixtures and surfactant-stabilized oil-in-water emulsions. Moreover, such membranes displayed excellent antifouling properties and were reusable for the separation of oil-water mixtures and surfactant-stabilized oil-in-water emulsions. With the advantages of facile fabrication, low-cost, fouling resistance and high separation performance, we believe that cysteine-based glass membranes without any hydrolytic bonds will arouse tremendous attentions for oil-water separation.

Hydrogels based on crosslinked polyethylene glycol diacrylate and fish skin gelatin

The aim of this work was to develop hydrogels based on poly(ethylene glycol diacrylate) (PEGDA) and fish gelatin for potential biomedical applications such as wound healing, drug delivery and biosensors. The hydrogels were prepared via in situ Michael addition of ammonia crosslinker to PEGDA in the presence of cold-water fish skin gelatin that was used as an additive. The fabrication conditions and properties of the hydrogels were examined using various amounts of fish gelatin to evaluate the influence of its concentration on gelation time, crosslinking density and swelling behavior of the hydrogels. FTIR spectra confirmed the formation of the crosslinked hydrogels and the degree of conversion (DC) of the double bonds for the hydrogels containing 5, 7.5 and 10 % w/v of gelatin was between 72 and 80 %. Fish skin gelatin had a strong effect on the dimentional stability and water absorbing properties of the hydrogels and the system containing 7.5 % w/v gelatin exhibited the longest swelling time of 18 h. The hydrophobicity of the hydrogels was achieved by covalent grafting of the residual double bonds with thiol-containing small hydrocarbon molecules using thiol-ene click chemistry reaction conditions, leading to the increase of the water contact angle from 0° to 60-73°.

Abstract 3250: LNA gapmer to gastrin inhibits growth and metastases of human pancreatic cancer in mice

Abstract Background: Pancreatic cancer has a poor prognosis and novel strategies are needed to improve the survival. Gastrin stimulates growth of pancreatic cancer by an autocrine mechanism and RNAi techniques that decrease gastrin expression have been shown to inhibit growth of this malignancy in vitro. Locked nucleic acid (LNA) Gapmers are antisense oligonucleotides (ASO) that have long half-life and stability in vivo, hence represent a potential method to deliver RNAi for cancer therapeutics. We developed an LNA Gapmer that selectively downregulates gastrin expression in pancreatic cancer cells in culture. The goal of this project was to test this anti-gastrin Gapmer in vivo as a novel therapy for pancreatic cancer. Methods: The anti-gastrin LNA Gapmer was modified using thiol-click chemistry to conjugate a peptide to the 5’ end and render the Gapmer target-specific with the ability to bind selectively to the cholecystokinin-B receptor that is over-expressed in pancreatic cancer. Forty athymic nude mice with established AsPC-1 human pancreatic orthotopic tumors were divided into four groups of equal tumor size. Mice (N=10 per group) were treated with PBS (controls), an untargeted LNA-Gapmer, the CCK-BR targeted Gapmer (60nM), and the CCK-BR targeted Gapmer (120nM) intraperitoneally twice a week for 4 weeks. Growth was monitored by luciferase IVIS imaging. At necropsy, tumors were excised, and metastases counted. Results: Mean tumor mass was 43% smaller in mice treated with the targeted Gapmer-120nM (P=0.0007). Untargeted and targeted Gapmer 60nM slightly decreased tumor mass but this difference was not significant. Compared to PBS control-treated mice, metastases were significantly less in mice treated with the untargeted Gapmer by -39% (p=0.01); in the targeted Gapmer-60nM by -44% (p=0.003), and with the targeted Gapmer-120nM by -72% (p<0.0001). Gastrin mRNA analysis of the tumors by qRT-PCR confirmed downregulation of gastrin. Conclusion: Novel LNA Gapmers that downregulate gastrin mRNA expression decrease growth and metastases of pancreatic cancer in a dose-related fashion. Citation Format: Godhanjali Chekuri, Wenqiang Chen, Narayan Shivapurkar, Hong Cao, Ruvanthi N. Kularatne, Stephan Stern, Jill P. Smith. LNA gapmer to gastrin inhibits growth and metastases of human pancreatic cancer in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3250.

Enhancing Adhesion of Fibrin-Based Hydrogel to Polythioether Polymer Surfaces.

The development of stable (bio)hybrid constructs composed of scaffolds and (bio)matrices is a major challenge in the field of tissue engineering. In the present work, the adhesion of fibrin-based hydrogels to the surface of polythioether-based polymers relevant to the 3D printing of polymer scaffolds produced by thiol-ene click chemistry was investigated. Adhesion properties were characterized by single-lap tensile shear testing. Both the sample preparation and the test method were optimized for the analysis of fibrin gel bonding to the polythioether surface. Our experimental results show that even without further modification, an adhesion between the fibrin hydrogel and polythioether is substantial, with an adhesion strength of 4.9 ± 1.0 kPa. To further improve the bonding, linear functional poly(N-vinylpyrrolidone-co-glycidyl methacrylate) (PVP-co-GMA) copolymers were used that are known for covalently binding to fibrin. The maximum adhesion strength in our study was found to be 18.4 ± 3.4 kPa. The pure PVP-co-GMA copolymers also demonstrate covalent binding to the thiol-ene-based polymers with a maximum adhesion strength of 32.2 ± 2.7 kPa. Therefore, compared to pure fibrin, the presence of copolymer coating both on the polythioether surface and in the fibrin gel led to a significant increase of the adhesion strength by a factor of 1.6.

Mechanically Interlocked Interphase with Energy Dissipation and Fast Li-Ion Transport for High-Capacity Lithium Metal Batteries.

Constructing an artificial solid electrolyte interphase (ASEI) on Li metal anodes (LMAs) is a potential strategy for addressing the dendrite issues. However, the mechanical fatigue of the ASEI caused by stress accumulation under the repeated deformation from the Li plating/stripping is not taken seriously. Herein, this work introduces a mechanically interlocked [an]daisy chain network (DC MIN) into the ASEI to stabilize the Li metal/ASEI interface by combining the functions of energy dissipation and fast Li-ion transport. The DC MIN featured by large-range molecular motions is cross-linked via efficient thiol-ene click chemistry; thus, the DC MIN has flexibility and excellent mechanical properties. As an ASEI, the crown ether units in DC MIN not only interact with the dialkylammonium of a flexible chain, forming the energy dissipation behavior but also coordinate with Li ion to support the fast Li-ion transport in DC MIN. Therefore, a stable 2800h-symmetrical cycling (1mA cm-2 ) and an excellent 5 C-rate (full cell with LiFePO4 ) performance are achieved by DC MIN-based ASEI. Furthermore, the 1-Ah pouch cell (LiNi0.88 Co0.09 Mn0.03 O2 cathode) with DC MIN-coated LMA exhibits improved capacity retention (88%) relative to the Control. The molecular design of DC MIN provides new insights into the optimization of an ASEI for high-energy LMAs.

Stereocomplexed Functional and Statistical Poly(lactide-carbonate)s via a Simple Organocatalytic System.

The stereocomplexation of polylactide (PLA) has been widely relied upon to develop degradable, sustainable materials with increased strength and improved material properties in comparison to stereopure PLA. However, forming functionalized copolymers of PLA while retaining high crystallinity remains elusive. Herein, the controlled ring-opening copolymerization (ROCOP) of lactide (LA) and functionalized cyclic carbonate monomers is undertaken. The produced polymers are shown to remain crystalline up to 25 mol % carbonate content and are efficiently stereocomplexed with homopolymer PLA and copolymers of opposite chirality. Polymers with alkene and alkyne pendent handles are shown to undergo efficient derivatization with thiol-ene click chemistry, which would allow both the covalent conjugation of therapeutic moieties and tuning of material properties.