Catechol Compounds Research Articles

Electrospray deposition of starch-containing laccase: A green technique for low-cost and eco-friendly biosensors

Recently a laccase-based biosensors with unprecedented reuse and storage capabilities in the detection of catechol compound has been manufactured using ambient Electrospray Deposition (ESD) technique. These biosensors showed to be reused up to 63 measurements on the same electrode just prepared at room temperature and pressure. In this new work the reasons behind such a high-performance functioning have been investigated by analysing the commercial sample of laccase with different chemical physics methods: Electrophoresis, Fourier Transform Infrared Spectroscopy, X-ray Fluorescence and Nuclear Magnetic Resonance Spectroscopy. The analyses reveal the presence of the starch in the sample and its essential role as stabilizing agent. Indeed, comparing the performance of starch/laccase-based biosensors with starch-free/laccase-based biosensors, both produced via ESD, showed that the starch-free biosensors lost about 40% of their performance after just the first wash. This suggests that the presence of starch in the laccase sample is a key factor in providing the high wash and storage resistance, which are essential for the fabrication of such devices.

Fabrication of ionic liquid-functionalized carbon dots as lubricant additive for friction and wear reduction

Herein, a long-chain ionic liquid with the catecholic group was successfully synthesized and then grafted to the carbon dots surface (CDs-ILs-Br) via the self-assembly capability of catecholic compound. The resulting CDs-ILs-Br exhibit excellent dispersion stability in PEG200, maintaining a uniform dispersion for over one month. With the addition of 3.0 wt% CDs-ILs-Br, the average COF of base oil decreased to 0.113, resulting in 60 % reduction in wear volume. Furthermore, the introduction of anti-wear agent BF4- further reduced average COF to 0.093. XPS and EDS analysis confirm complex tribochemical reactions between CDs-ILs-Br and the friction pair, and the grafting polar molecules of ILs on the carbon dots surface enhanced adhesion effect under high shear condition, forming a robust tribochemical protective film.

Di-caffeoylquinic acid: a potential inhibitor for amyloid-beta aggregation.

Alzheimer's disease (AD) remains a challenging neurodegenerative disorder with limited therapeutic success. Traditional Chinese Medicine (TCM), as a promising new source for AD, still requires further exploration to understand its complex components and mechanisms. Here, focused on addressing Aβ (1-40) aggregation, a hallmark of AD pathology, we employed a Thioflavin T fluorescence labeling method for screening the active molecular library of TCM which we established. Among the eight identified, 1,3-di-caffeoylquinic acid emerged as the most promising, exhibiting a robust binding affinity with a KD value of 26.7nM. This study delves into the molecular intricacies by utilizing advanced techniques, including two-dimensional (2D) 15N-1H heteronuclear single quantum coherence nuclear magnetic resonance (NMR) and molecular docking simulations. These analyses revealed that 1,3-di-caffeoylquinic acid disrupts Aβ (1-40) self-aggregation by interacting with specific phenolic hydroxyl and amino acid residues, particularly at Met-35 in Aβ (1-40). Furthermore, at the cellular level, the identified compounds, especially 1,3-di-caffeoylquinic acid, demonstrated low toxicity and exhibited therapeutic potential by regulating mitochondrial membrane potential, reducing cell apoptosis, and mitigating Aβ (1-40)-induced cellular damage. This study presents a targeted exploration of catechol compounds with implications for effective interventions in AD and sheds light on the intricate molecular mechanisms underlying Aβ (1-40) aggregation disruption.

Mussel Foot Protein-Inspired Adhesive Tapes with Tunable Underwater Adhesion.

Instant and strong adhesion to underwater adherends is a big challenge due to the continuous interference of water. Mussel foot protein-bioinspired catechol-based adhesives have garnered great interest in addressing this issue. Herein, a novel self-made catecholic compound with a long aliphatic chain was utilized to prepare thin (∼0.07 mm) and optically transparent (>80%) wet/underwater adhesive tapes by UV-initiated polymerization. Its adhesion activity was water-triggered, fast (<1 min), and strong (adhesion strength to porcine skin: ∼1.99 MPa; interfacial toughness: ∼610 J/m2, burst pressure: ∼1950 mmHg). The effect of the catechol/phenol group and positively charged moiety on the wet/underwater adhesion to abiotic/biotic substrates was investigated. On the wet/underwater adherends, the tape with catechol groups presented much higher interfacial toughness, adhesion strength, and burst pressure than the analogous tape with phenol groups. The tape with both the catechol group and cationic polyelectrolyte chitosan had a more impressive improvement in its adhesion to wet/underwater biological tissues than to abiotic substrates. Therefore, catechol and a positive moiety in the tape would synergistically enhance its wet/underwater adhesion to various substrates, especially to biological tissues. The instant, strong, and noncytotoxic tape may provide applications in underwater adhesion for sealing and wound closure.

Characteristics of lignin isolated from an agricultural by-product: Camellia oleifera shell

Camellia oleifera fruit shell (COFS) and Camellia oleifera seed shell (COSS) are agricultural residues in the tea-oil processing, and rich in lignin. Analyzing the characteristics of the milling wood lignin from COFS (COFS-MWL) and COSS (COSS-MWL) was a fundamental step in achieving efficient application of the shells. The analysis showed that COFS-MWL was a kind of G/S type lignin, while COSS-MWL contained catechyl lignin (C-lignin) coexisting with G/S type lignin. This means that COSS was expected to become an important source of C- lignin. In addition, activation energies of COFS-MWL and COSS-MWL pyrolysis reaction were calculated based on Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose model. The mean values obtained from two methods were similar about 174 kJ/mol and 268 kJ/mol, respectively. The main thermal degradation products of COSS-MWL were catechols at the pyrolytic temperature of 700 °C. The result confirmed again that COSS-MWL had rich unique C-lignin structure. In general, this study will be of great significance for the production of catechol compounds from biomass and the high value-added development of agricultural residues.

Catechol compounds as dual-targeting agents for fish protection against Ichthyophthirius multifiliis infections

Aquaculture is one of the fastest growing sectors in global food production, recognized as a significant contributor to poverty alleviation, food security, and income generation. However, the frequent occurrence of diseases caused by pathogen infections result in reduced yields and economic losses, posing a substantial constraint to the sustainable development of aquaculture. Here, our study identified that four catechol compounds, quercetin, luteolin, caffeic acid, and chlorogenic acid, exhibited potent antiparasitic effects against Ichthyophthirius multifiliis in both, in vitro and in vivo. The parasite is recognized as one of the most pathogenic to fish worldwide. Using a combination of in silico methods, the dipeptidyl peptidase (DPP) was identified as a critical target for catechol compounds. The two hydroxyl radicals of the catechol group were essential for its binding to and interacting with the DPP protein. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that catechol compounds disrupt pathways associated with the metabolism and growth of I. multifiliis, thereby exerting antiparasitic effects. Furthermore, these compounds attenuated the expression of proinflammatory cytokines in vivo in fish and promoted macrophage polarization toward M2 phenotype by inhibiting the STAT1 signaling pathway. The dual activity of catechol compounds, acting as both direct antiparasitic and anti-inflammatory agents in fish, offers a promising therapeutic approach for combating I. multifiliis infections in aquaculture.

Multifunctional Dopamine-Based Hydrogel Microneedle Electrode for Continuous Ketone Sensing.

Diabetic ketoacidosis (DKA), a severe complication of type 1 diabetes (T1D), is triggered by production of large quantities of ketone bodies, requiring patients with T1D to constantly monitor their ketone levels. Here, a skin-compatible hydrogel microneedle (HMN)-continuous ketone monitoring (HMN-CKM) device is reported. The sensing mechanism relies on the catechol-quinone chemistry inherent tothe dopamine (DA) molecules that are covalently linked to the polymer structure of the HMN patch. The DA serves the dual-purpose of acting as a redox mediator for measuring the byproduct of oxidation of 3-beta-hydroxybutyrate (β-HB), the primary ketone bodies; while, also facilitating the formation of a crosslinked HMN patch. A universal approach involving pre-oxidation and detection of the generated catechol compounds is introduced to correlate the sensor response to the β-HB concentrations. It is further shown that real-time tracking of a decrease in ketone levels of T1D rat model is possible using the HMN-CKM device, in conjunction with a data-driven machine learning model that considers potential time delays.

The Peculiar H-Bonding Network of 4-Methylcatechol: A Coupled Diffraction and In Silico Study.

The crystal structure of 4-methylcatechol (4MEC) has, to date, never been solved, despite its very simple chemical formula C7O2H8 and the many possible applications envisaged for this molecule. In this work, this gap is filled and the structure of 4MEC is obtained by combining X-ray powder diffraction and first principle calculations to carefully locate hydrogen atoms. Two molecules are present in the asymmetric unit. Hirshfeld analysis confirmed the reliability of the solved structure, since the two molecules show rather different environments and H-bond interactions of different directionality and strength. The packing is characterised by a peculiar hydrogen bond network with hydroxyl nests formed by two adjacent octagonal frameworks. It is noteworthy that the observed short contacts suggest strong inter-molecular interactions, further confirmed by strong inter-crystalline aggregation observed by microscopic images, indicating the growth, in many crystallization attempts, of single aggregates taller than half a centimetre and, often, with spherical shapes. These peculiarities are induced by the presence of methyl group in 4MEC, since the parent compound catechol, despite its chemical similarity, shows a standard layered packing alternating hydrophobic and polar layers. Finally, the complexity and peculiarity of the packing and crystal growth features explain why a single crystal could not be obtained for a standard structural analysis.

Microbial synthesis of antimony sulfide to prepare catechol and hydroquinone electrochemical sensor by pyrolysis and carbonization

The application of antimony sulfide sensors, characterized by their exceptional stability and selectivity, is of emerging interest in detection research, and the integration of graphitized carbon materials is expected to further enhance their electrochemical performance. This study represents a pioneering effort in the synthesis of carbon-doped antimony sulfide materials through the pyrolysis of the mixture of microorganisms and their synthetic antimony sulfide. The prepared materials are subsequently applied to electrochemical sensors for monitoring the highly toxic compounds catechol (CC) and hydroquinone (HQ) in the environment. Via cyclic voltammetry (CV) and impedance testing, we concluded that the pyrolytic product at 700 °C (Sb-700) demonstrated the best electrochemical properties. Differential pulse voltammetry (DPV) revealed impressive separation when utilizing Sb-700/GCE for simultaneous detection of CC and HQ, exhibiting good linearity within the concentration range of 0.1–140 μM. The achieved sensitivities of 24.62 μA μM−1 cm−2 and 22.10 μA μM−1 cm−2 surpassed those of most CC and HQ electrochemical sensors. Meanwhile, the detection limits for CC and HQ were as low as 0.18 μM and 0.16 μM (S/N = 3), respectively. Additional tests confirmed the good selectivity, reproducibility, and long-term stability of Sb-700/GCE, which was effective in detecting CC and HQ in tap water and river water, with recovery rates of 100.7%–104.5% and 96.5%–101.4%, respectively. It provides a method that combines green microbial synthesis and simple pyrolysis for the preparation of electrode materials in CC and HQ electrochemical sensors, and also offers a new perspective for the application of microbial synthesized materials.

Polymerizable rotaxane of cucurbituril protecting dopamine based adhesive hydrogels

The catechol moiety found within mussel proteins plays a pivotal role in enhancing their adhesive properties. Nonetheless, catechol compounds, such as dopamine (DOP) derivatives, are susceptible to oxidation, leading to the formation of quinone. This oxidation process poses a significant challenge in the development of DOP-based hydrogels, hampering their adhesion capabilities and hindering polymerization. To protect DOP moieties from oxidation, DOP and N-(3-aminopropyl)methacrylamide (AMA) moieties were grafted onto the side groups of biocompatible poly(glutamic acid) (PGA). Subsequently, the DOP unit, serving as a second guest, would be captured by a polymerizable rotaxane of cucurbituril (CB[n]), in which the host molecule CB[8] complexed with the first guest, polymerizable methyl viologen (MV), forming a protective function and dynamic cross-linking. Upon exposure to light curing, a composite network emerged through the synergy of covalent cross-linking and supramolecular host-guest complexation of DOP with CB[8]. The generated complexation between DOP and CB[8] could protect the DOP moieties, resulting in photocured hydrogels with exceptional adhesive strength and remarkable tensile capabilities. Moreover, 3D printing technology was used to create various models with these DOP-based hydrogels, demonstrating their promising applications in future.

Engineering non-conservative substrate recognition sites of extradiol dioxygenase: Computation guided design to diversify and accelerate degradation of aromatic compounds

Extradiol dioxygenases (EDOs) catalyzing meta-cleavage of catecholic compounds promise an effective way to detoxify aromatic pollutants. This work reported a novel scenario to engineer our recently identified Type I EDO from Tcu3516 for a broader substrate scope and enhanced activity, which was based on 2,3-dihydroxybiphenyl (2,3-DHB)-liganded molecular docking of Tcu3516 and multiple sequence alignment with other 22 Type I EDOs. 11 non-conservative residues of Tcu3516 within 6 Å distance to the 2,3-DHB ligand center were selected as potential hotspots and subjected to semi-rational design using 6 catecholic analogues as substrates; the mutants V186L and V212N returned with progressive evolution in substrate scope and catalytic activity. Both mutants were combined with D285A for construction of double mutants and final triple mutant V186L/V212N/D285A. Except for 2,3-DHB (the mutant V186L/D285A gave the best catalytic performance), the triple mutant prevailed all other 5 catecholic compounds for their degradation; affording the catalytic efficiency kcat/Km value increase by 10–30 folds, protein Tm (structural rigidity) increase by 15 °C and the half-life time enhancement by 10 times compared to the wild type Tcu3516. The molecular dynamic simulation suggested that a stabler core and a more flexible entrance are likely accounting for enhanced catalytic activity and stability of enzymes.

Meirols A-C: Bioactive Catecholic Compounds from the Marine-Derived Fungus Meira sp. 1210CH-42.

Three new catecholic compounds, named meirols A-C (2-4), and one known analog, argovin (1), were isolated from the marine-derived fungus Meira sp. 1210CH-42. Their structures were determined by extensive analysis of 1D, 2D NMR, and HR-ESIMS spectroscopic data. Their absolute configurations were elucidated based on ECD calculations. All the compounds exhibited strong antioxidant capabilities with EC50 values ranging from 6.01 to 7.47 μM (ascorbic acid, EC50 = 7.81 μM), as demonstrated by DPPH radical scavenging activity assays. In the α-glucosidase inhibition assay, 1 and 2 showed potent in vitro inhibitory activity with IC50 values of 184.50 and 199.70 μM, respectively (acarbose, IC50 = 301.93 μM). Although none of the isolated compounds exhibited cytotoxicity against one normal and six solid cancer cell lines, 1 exhibited moderate cytotoxicity against the NALM6 and RPMI-8402 blood cancer cell lines with GI50 values of 9.48 and 21.00 μM, respectively. Compound 2 also demonstrated weak cytotoxicity against the NALM6 blood cancer cell line with a GI50 value of 29.40 μM.

Formulation Development and Evaluation of Highly Oxidative Degradative Drug Molecule Injectable Dosage form by Lyophilisation Techniques

Adrenaline (ADR) It is lifesaving and is the only first-line drug for the treatment of anaphylaxis. Adrenaline (ADR) is the endogenous catecholamine with potent alpha- and beta-adrenergic stimulating properties. Alpha-adrenergic action increases systemic and pulmonary vascular resistance, increasing both systolic and diastolic blood pressure. Adrenaline is released in the bloodstream, which increases heartbeat, muscle strength, blood pressure, and glucose metabolism. Oxidation degradation of the medicinal product is the main route of degradation. Affects chemical and physical changes in drugs during the formulation development process. Physicochemical changes in the product can affect both the safety and efficacy of the drug product. Main product development strategy to develop, a stable, freeze-dried product of epinephrine for injection. The stability of adrenaline injection is of paramount objective as it is classified as a catechol compound that is sensitive to oxidation to o-quinone and therefore can react further to form highly colored compounds. Adrenergic drugs further react to form adrenochrome, a highly colored indole derivative. The rate of this reaction increased with pH, temperature and presence of the metal ions. Aqueous solutions of adrenergic agonists decompose rapidly when exposed to air, light, or heat, turning pink due to oxidation to adrenochrome and brown due to melanin formation. Due to its strong oxidizing properties and easy decomposition in aqueous solutions. To achieve this, the aqueous solutions of adrenergic agonists decompose rapidly when exposed to air, light, or heat, turning pink due to oxidation to adrenochrome and brown due to melanin formation. Due to its strong oxidizing properties and easy decomposition in aqueous solutions.

Engineering of 4-hydroxyphenylacetate-3-hydroxylase from Escherichia coli for efficient biosynthesis of piceatannol

Piceatannol, a catechol compound, exhibits various health benefits, with great application value in food, medicine, and cosmetics. However, the low natural abundance of piceatannol limits its cost-effective isolation, and chemical synthesis is difficult. Here, we report an efficient biocatalytic system for the production of piceatannol from resveratrol. Structure-based semi-rational engineering was used to generate HpaBCG209F, a novel HpaBC mutant of 4-hydroxyphenylacetate-3-hydroxylase from Escherichia coli. Biocatalytic activity assays revealed that HpaBCG209F exhibits 3.12 times higher activity toward resveratrol than wild-type HpaBC. We also introduced formic acid dehydrogenase (FDH) as an NADH-regeneration system for HpaBCG209F to support piceatannol production. Co-expression of HpaBCG209F and FDH in E. coli BL21(DE3) enabled the generation of 8.23 mM piceatannol from 10.2 mM resveratrol within 9.5 h under optimized conditions, representing an 80.6% molar conversion ratio. This study therefore successfully developed a highly active HpaBC variant for hydroxylating resveratrol to piceatannol, as well as demonstrated a promising biopathway for piceatannol production.

Tyrosinase from Citreicella sp. as an organophilic enzyme for catechol biosynthesis

Tyrosinases can directly catalyze the biosynthesis of catechol compounds without additional cofactors under mild conditions. However, the low stability of tyrosinases in organic media has limited their use. Herein, a tyrosinase (csTyr) was identified from Citreicella sp. SE45 that possesses a characteristic feature of halophilic proteins and can be functionally expressed in Escherichia coli. Remarkably, the enzymatic activity of csTyr was effectively induced by primary alcohols in cosolvent media, whereas csTyr did not have enzymatic activity in aqueous media, minimizing unwanted reactions during tyrosinase preparation. In particular, the catalytic efficiency and stability of csTyr in a 50 % (v/v) ethanol-water cosolvent were comparable to those of other tyrosinases in water. Using csTyr as a catalyst for ortho-hydroxylation reactions of acetaminophen and resveratrol, the high catalytic activity and stability in 50 % (v/v) ethanol efficiently enabled the production of 3-hydroxy-acetaminophen and piceatannol. Therefore, csTyr, an organophilic tyrosinase, can be greatly useful in the biosynthesis of catechol compounds by addressing the issue of poor enzymatic stability in organic media.

Infrared spectroscopy analysis determining secondary structure change in albumin by cerium oxide nanoparticles.

Cerium oxide (CeO2) nanoparticles are expected to have applications in the biomedical field because of their antioxidative properties. Inorganic nanoparticles interact with proteins at the nanoparticle surface and change their conformation when administered; however, the principle underlying this interaction is still unclear. This study aimed to investigate the secondary structural changes occurring in bovine serum albumin (BSA) mixed with CeO2 nanoparticles having different surface modifications using Fourier transform infrared spectroscopy. CeO2 nanoparticles (diameter: 240nm) were synthesized from an aqueous cerium (III) nitrate solution using a homogeneous precipitation method. The surfaces of the nanoparticles were modified by the catechol compounds dopamine and 3,4-dihydroxyhydrocinnamic acid (DHCA). In the presence of these CeO2 nanoparticles (0.11-0.43mg/mL), β-sheet formation of BSA (30mg/mL) was promoted especially on the amine-modified (positively charged) nanoparticles. The local concentration of BSA on the surface of the positively charged nanoparticles may have resulted in structural changes due to electrostatic and other interactions with BSA. Further investigations of the interaction mechanism between nanoparticles and proteins are expected to lead to the safe biomedical applications of inorganic nanoparticles.

The role of tyrosine in protein-dopamine based bioinspired adhesives: the stoichiometry that maximizes bonding strength

Nature has evolved adhesive materials adaptive for several different environments by using versatile chemistry that largely relies on two simple components: catechols and polypeptides. Herein, using dopamine as a catechol compound and several model proteins, we show how the adhesive properties can be tuned by controlling the ratio between catechol units and the tyrosine amino acid residue in the protein components. We found that the best bonding strength performance is obtained using a dopamine molar excess to tyrosine of 8.6 ± 2.9. Our study points out a general design criterion and process to obtain high-performance adhesives (&amp;gt;2 MPa) starting from cheap, commercially available, and sustainable raw materials.

Chitosan-based mussel-inspired hydrogel for rapid self-healing and high adhesion of tissue adhesion and wound dressings

The hydrogel wound dressing with self-healing and adhesive property can provide better protection to the wound and prolong the service life of the material. Inspired by mussels, a high-adhesion, injectable, self-healing and antibacterial hydrogel was designed in this study. The lysine (Lys) and the catechol compound 3,4-dihydroxyphenylacetic acid (DOPAC) were grafted onto chitosan (CS). The presence of catechol group endows the hydrogel strong adhesion and antioxidation. In the experiment of wound healing in vitro, the hydrogel can adhere to the wound surface and promote wound heal. In addition, it has been proved the hydrogel has good antibacterial properties against S. aureus and E. coli. The treatment of CLD hydrogel, the degree of wound inflammation was significantly alleviated. The levels of TNF-α, IL-1β, IL-6 and TGF-β1 were reduced from 39.8379 %, 31.6768 %, 32.1015 % and 38.4911 % to 18.5931 %, 12.2275 %, 13.0524 % and 16.9959 %, respectively. And the levels of PDGFD and CD31 were increased from 35.6054 %, 21.7394 % to 51.8555 %, 43.9326 %, respectively. These results indicated that the CLD hydrogel has a good ability to promote angiogenesis, thickening of skin and epithelial structures.

A comprehensive genomic analysis provides insights on the high environmental adaptability of Acinetobacter strains.

Acinetobacter is ubiquitous, and it has a high species diversity and a complex evolutionary pattern. To elucidate the mechanism of its high ability to adapt to various environment, 312 genomes of Acinetobacter strains were analyzed using the phylogenomic and comparative genomics methods. It was revealed that the Acinetobacter genus has an open pan-genome and strong genome plasticity. The pan-genome consists of 47,500 genes, with 818 shared by all the genomes of Acinetobacter, while 22,291 are unique genes. Although Acinetobacter strains do not have a complete glycolytic pathway to directly utilize glucose as carbon source, most of them harbored the n-alkane-degrading genes alkB/alkM (97.1% of tested strains) and almA (96.7% of tested strains), which were responsible for medium-and long-chain n-alkane terminal oxidation reaction, respectively. Most Acinetobacter strains also have catA (93.3% of tested strains) and benAB (92.0% of tested strains) genes that can degrade the aromatic compounds catechol and benzoic acid, respectively. These abilities enable the Acinetobacter strains to easily obtain carbon and energy sources from their environment for survival. The Acinetobacter strains can manage osmotic pressure by accumulating potassium and compatible solutes, including betaine, mannitol, trehalose, glutamic acid, and proline. They respond to oxidative stress by synthesizing superoxide dismutase, catalase, disulfide isomerase, and methionine sulfoxide reductase that repair the damage caused by reactive oxygen species. In addition, most Acinetobacter strains contain many efflux pump genes and resistance genes to manage antibiotic stress and can synthesize a variety of secondary metabolites, including arylpolyene, β-lactone and siderophores among others, to adapt to their environment. These genes enable Acinetobacter strains to survive extreme stresses. The genome of each Acinetobacter strain contained different numbers of prophages (0-12) and genomic islands (GIs) (6-70), and genes related to antibiotic resistance were found in the GIs. The phylogenetic analysis revealed that the alkM and almA genes have a similar evolutionary position with the core genome, indicating that they may have been acquired by vertical gene transfer from their ancestor, while catA, benA, benB and the antibiotic resistance genes could have been acquired by horizontal gene transfer from the other organisms.

Injectable gelatin-oligo-catechol conjugates for tough thermosensitive bioadhesion

Extracellular matrix-derived biomaterials, such as gelatin-based hydrogels, are attractive candidates for sealing internal leakages. However, gelatin derivatives are brittle and suffer from poor adhesion. Modifications of gelatin with adhesive catechol moieties have been limited to low degrees of substitution. Here, we propose oxidative oligomerization of catecholic compounds (namely, caffeic acid [CA]) prior to the coupling reaction to augment the number and availability of grafted catechol groups per carbodiimide conjugation reaction, thereby achieving robust bioadhesion. Ex vivo adhesion tests on pig lungs suggests ∼3× improvement in adhesion strength compared with gelatin methacryloyl controls due to their enhanced cohesion (i.e., ∼5.3× and ∼11.5× improvements in stretchability and toughness, respectively). Functionalization of gelatin with CA oligomers enables rapid formation of physical gels upon exposure to room temperature, tunes the viscosity of the gelatin-caffeic acid pre-gel solution for controllable injectability onto multiply curved tissues, and boosts the antioxidant effects of CA.