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1.
Small ; : e2401387, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38773909

ABSTRACT

Bulk hexagonal boron nitride (h-BN) ceramics with structural integrity, high-temperature resistance and low expansion rate are expected for multifunctional applications in extreme conditions. However, due to its sluggish self-diffusion and intrinsic inertness, it remains a great challenge to overcome high-energy barrier for h-BN powder sintering. Herein, a cross-linking and pressureless-welding strategy is reported to produce bulk boron nitride nanosheets (BNNSs) ceramics with well-crystalized and dense B-N covalent-welding frameworks. The essence of this synthesis strategy lies in the construction of >B─O─H2C─H2C─H2N:→B< bond bridge connection structure among hydroxyl functionalized BNNSs (BNNSs-OH) using bifunctional monoethanolamine (MEA) as cross-linker through esterification and intermolecular-coordination reactions. The prepared BNNSs-interlaced ceramics have densities not less than 1.2 g cm-3, and exhibit exceptional mechanical robustness and resiliency, excellent thermomechanical stability, ultra-low linear thermal expansion coefficient of 0.06 ppm °C-1, and high thermal diffusion coefficient of 4.76 mm2 s-1 at 25 °C and 3.72 mm2 s-1 at 450 °C. This research not only reduces the free energy barrier from h-BN particles to bulk ceramics through facile multi-step physicochemical reaction, but also stimulates further exploration of multifunctional applications for bulk h-BN ceramics over a wide temperature range.

2.
J Mater Chem B ; 12(16): 3947-3958, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38586917

ABSTRACT

Colorectal cancer (CRC) occurs in the colorectum and ranks second in the global incidence of all cancers, accounting for one of the highest mortalities. Although the combination chemotherapy regimen of 5-fluorouracil (5-FU) and platinum(IV) oxaliplatin prodrug (OxPt) is an effective strategy for CRC treatment in clinical practice, chemotherapy resistance caused by tumor-resided Fusobacterium nucleatum (Fn) could result in treatment failure. To enhance the efficacy and improve the biocompatibility of combination chemotherapy, we developed an antibacterial-based nanodrug delivery system for Fn-associated CRC treatment. A tumor microenvironment-activated nanomedicine 5-FU-LA@PPL was constructed by the self-assembly of chemotherapeutic drug derivatives 5-FU-LA and polymeric drug carrier PPL. PPL is prepared by conjugating lauric acid (LA) and OxPt to hyperbranched polyglycidyl ether. In principle, LA is used to selectively combat Fn, inhibit autophagy in CRC cells, restore chemosensitivity of 5-FU as well as OxPt, and consequently enhance the combination chemotherapy effects for Fn-associated drug-resistant colorectal tumor. Both in vitro and in vivo studies exhibited that the tailored nanomedicine possessed efficient antibacterial and anti-tumor activities with improved biocompatibility and reduced non-specific toxicity. Hence, this novel anti-tumor strategy has great potential in the combination chemotherapy of CRC, which suggests a clinically relevant valuable option for bacteria-associated drug-resistant cancers.


Subject(s)
Antineoplastic Agents , Colorectal Neoplasms , Fluorouracil , Lauric Acids , Fluorouracil/pharmacology , Fluorouracil/chemistry , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Humans , Lauric Acids/chemistry , Lauric Acids/pharmacology , Animals , Mice , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Fusobacterium nucleatum/drug effects , Oxaliplatin/pharmacology , Oxaliplatin/chemistry , Drug Delivery Systems , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Prodrugs/chemistry , Prodrugs/pharmacology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Mice, Inbred BALB C , Particle Size , Drug Carriers/chemistry
3.
Nano Lett ; 23(22): 10608-10616, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37948661

ABSTRACT

The rarity of efficient tools with spatiotemporal resolution and biocompatibility capabilities remains a major challenge for further progress and application of signaling manipulation. Herein, biomimetic conjugated oligomeric nanoparticles (CM-CONs) were developed to precisely modulate blood glucose homeostasis via the two-pronged activation of calcium channels. Under near-infrared (NIR) laser irradiation, CM-CONs efficiently generate local heat and reactive oxygen species (ROS), thereby simultaneously activating thermosensitive transient receptor potential V1 (TRPV1) and ROS-sensitive transient receptor potential A1 (TRPA1) calcium channels in small intestinal endocrine cells. The activation of the channels mediates inward calcium flow and then promotes glucagon-like peptide (GLP-1) secretion. Both in vitro and in vivo studies indicate that CM-CONs effectively regulate glucose homeostasis in diabetic model mice upon NIR light irradiation. This work develops a two-pronged attack strategy for accurately controlling blood glucose homeostasis, holding great prospects in the treatment for diabetes.


Subject(s)
Blood Glucose , Nanoparticles , Mice , Animals , Reactive Oxygen Species/metabolism , Calcium Channels , Homeostasis , Calcium/metabolism
4.
Polymers (Basel) ; 15(18)2023 Sep 14.
Article in English | MEDLINE | ID: mdl-37765621

ABSTRACT

In this paper, a polyacrylic elastomer latex with butyl acrylate (BA) as the core and methyl methacrylate (MMA) copolymerized with glycidyl methacrylate (GMA) as the shell, named poly(BA-MMA-GMA) (PBMG), was synthesized by seeded emulsion polymerization. Cellulose nanocrystal (CNC) was dispersed in the polyacrylic latex to prepare PBMG/CNC dispersions with different CNC contents. The dried product was mixed with polylactic acid (PLA) to fabricate PLA/PBMG/CNC blends. The addition of PBMG and PBMG/CNC improved the mechanical properties of the PLA matrix. Differential scanning calorimetry (DSC) was used to investigate the non-isothermal crystallization kinetics. The Avrami equation modified by the Jeziorny, Ozawa and Mo equations was used to analyze the non-isothermal crystallization kinetics of PLA and its blends. Analysis of the crystallization halftime of non-isothermal conditions indicated that the overall rate of crystallization increased significantly at 1 wt% content of CNC. This seemed to result from the increase of nucleation density and the acceleration of segment movement in the presence of the CNC component. This phenomenon was verified by polarizing microscope observation.

5.
Adv Healthc Mater ; 12(31): e2301954, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37722719

ABSTRACT

Cell fate can be efficiently modulated by switching ion channels. However, the precise regulation of ion channels in cells, especially in specific organelles, remains challenging. Herein, biomimetic second near-infrared (NIR-II) responsive conjugated oligomer nanoparticles with dual-targeted properties are designed and prepared to modulate the ion channels of mitochondria to selectively kill malignant cells in vivo. Upon 1060 nm laser irradiation, the mitochondria-located nanoparticles photothermally release a specific ion inhibitor of the potassium channel via a temperature-sensitive liposome, thus altering the redox balance and pathways of mitochondria. NIR-II responsive nanoparticles can effectively regulate the potassium channels of mitochondria and fully suppress tumor growth. This work provides a new modality based on the NIR-II nanoplatform to regulate ion channels in specific organelles and proposes an effective therapeutic mechanism for malignant tumors.


Subject(s)
Nanoparticles , Neoplasms , Humans , Precision Medicine , Potassium Channels , Neoplasms/drug therapy , Neoplasms/pathology , Nanoparticles/metabolism , Mitochondria , Cell Line, Tumor , Phototherapy
6.
Opt Lett ; 48(17): 4697-4700, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37656589

ABSTRACT

Four phthalocyanine derivatives with different electron donor and acceptor substituents (B1, B2, B3, and B4) were synthesized by a solid-phase melting method. The influence of substituent type on the nonlinear optical properties of the materials was investigated in detail. In the case of similar conjugated structures, B3, which has amino electron-donor groups, presents high intramolecular charge transfer, a low energy gap (2.05 eV), and good nonlinear optical properties. Compared with B3, B4 has a larger π-conjugated structure and its energy gap is 0.04 eV smaller. Moreover, B4 has stronger reverse saturation absorption (7 × 10-12 m/W) and optical limiting performance. The four phthalocyanine derivatives exhibit third harmonic generation (THG) characteristics. Furthermore, the third harmonic strengths of B1, B2, B3, and B4 are 4 times, 9 times, 11 times, and 21 times that of SiO2, respectively. So, B4 has the best application potential in laser protection and frequency conversion.

7.
Polymers (Basel) ; 15(14)2023 Jul 10.
Article in English | MEDLINE | ID: mdl-37514392

ABSTRACT

It is crucial to develop sensitive and accurate sensing strategies to detect H2O2 and glucose in biological systems. Herein, biocompatible iron-coordinated L-lysine-based hydrogen peroxide (H2O2)-mimetic enzymes (Lys-Fe-NPs) were prepared by precipitation polymerization in aqueous solution. The coordinated Fe2+ ion acted as centers of peroxidase-like enzymes of Lys-Fe-NPs, and the catalytic activity was evaluated via the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2. Therefore, a sensitive colorimetric detection sensor for H2O2 was constructed with a linear range of 1 to 200 µM and a detection limit of 0.51 µM. The same method could also be applied to highly sensitive and selective detection of glucose, with a linear range of 0.5 to 150 µM and a detection limit of 0.32 µM. In addition, an agarose-based hydrogel biosensor colorimetric was successfully implemented for visual assessment and quantitative detection of glucose. The design provided a novel platform for constructing stable and nonprotein enzyme mimics with lysine and showed great potential applications in biorelevant assays.

8.
ACS Appl Mater Interfaces ; 15(31): 37845-37854, 2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37489898

ABSTRACT

Developing effective synthetic strategies as well as broadening functionalities for zwitterionic materials that comprise moieties with equimolar cationic and anionic groups still remains a huge challenge. Herein, we develop two zwitterionic vinylene-linked covalent organic frameworks (Zi-VCOF-1 and Zi-VCOF-2) that are a type of novel hydrophilic material. Zi-VCOF-1 and Zi-VCOF-2 are obtained directly through the convenient Knoevenagel condensation of new sulfonic-pyridinium zwitterionic monomers with aromatic aldehyde derivatives. This is the first report on zwitterionic COFs being constructed by the bottom-up functionalization approach from predesigned zwitterionic monomers. Both Zi-VCOFs exhibit a high photocatalytic hydrogen evolution rate (HER) because of their appropriate optical property and outstanding hydrophilicity. Specifically, Zi-VCOF-1 and Zi-VCOF-2 show photocatalytic HER of 13,547 and 5057 µmol h-1 g-1, respectively. Interestingly, the photocatalytic HER of Zi-VCOF-1 is about 2.68 times of that of Zi-VCOF-2, although they differ by only one methyl group in sulfonic-pyridinium zwitterionic pairs. The photocatalytic HER of Zi-VCOF-1 is not only the highest in the vinylene-linked COFs but also outstanding among the most reported COFs. This is the first application of zwitterionic COFs for photocatalytic hydrogen evolution, which would open a new frontier in zwitterionic COFs and be helpful for the design of other photocatalytic materials.

9.
ACS Appl Mater Interfaces ; 15(30): 36738-36747, 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37487247

ABSTRACT

Shaping covalent organic frameworks (COFs) into macroscopic objects for practical application remains a huge challenge. Herein, a new thiadiazole-derived COF macroscopic ultralight aerogel (NNS-VCOF) was prepared through acid-catalyzed aldol condensation between 2,5-dimethyl-1,3,4-thiadiazole and a tritopic aromatic aldehyde derivative. NNS-VCOF aerogel shows extremely low density (ca. 0.020 g cm-3), excellent mechanical properties (compression modulus of 16.65 kPa), thermal insulation properties (low thermal conductivity of 0.03270 W m-1 K-1 at 25 °C), and flame retardancy (quickly self-extinguishing after ignition) due to its three-dimensional sponge-like architecture and special nitrogen heterocyclic framework. To our delight, NNS-VCOF aerogel not only can be used as an outstanding macroscopic material but also shows efficient photocatalytic hydrogen evolution properties in a powder state because of the superhydrophilicity and appropriate optical properties.

10.
Appl Opt ; 62(10): 2493-2500, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-37132797

ABSTRACT

The pyrene derivative (PD) was synthesized with pyrene-1-carboxaldehyde and p-aminoazobenzene by a Schiff base reaction. Then the obtained PD was dispersed in polyurethane (PU) prepolymer to prepare polyurethane/pyrene derivative PU/PD materials with good transmittance. The nonlinear optical (NLO) performances of the PD and PU/PD materials were studied by the Z-scan technique under picosecond and femtosecond laser pulses. The PD has reverse saturable absorption (RSA) properties under the excitation of 532 nm 15 ps pulses, 650 and 800 nm 180 fs pulses, and a low optical limiting (OL) threshold (0.01J/c m 2). The PU/PD has a larger RSA coefficient than that of the PD under 532 nm 15 ps pulses. With the enhanced RSA, the PU/PD materials exhibit excellent OL (OL) performance. Good NLO properties, high transparency, and easy processing performances make the PU/PD an excellent choice for use in OL and laser protection fields.

11.
Polymers (Basel) ; 15(5)2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36904305

ABSTRACT

A europium complex with double bonds was synthesized with crotonic acid as the ligand and a europium ion as the center ion. Then, the obtained europium complex was added to synthesized poly(urethane-acrylate) macromonomers to prepare the bonded polyurethane-europium materials by the polymerization of the double bonds in the complex and the poly(urethane-acrylate) macromonomers. The prepared polyurethane-europium materials had high transparency, good thermal stability and good fluorescence. The storage moduli of polyurethane-europium materials are obviously higher than those of pure polyurethane. Polyurethane-europium materials exhibit bright red light with good monochromaticity. The light transmittance of the material decreases slightly with increases in the europium complex content, but the luminescence intensity gradually increases. In particular, polyurethane-europium materials possess a long luminescence lifetime, which has potential applications for optical display instruments.

12.
Adv Sci (Weinh) ; 10(11): e2206585, 2023 04.
Article in English | MEDLINE | ID: mdl-36776018

ABSTRACT

Bacterial infection often induces chronic repair of wound healing owing to aggravated inflammation. Hydrogel dressing exhibiting intrinsic antibacterial activity may substantially reduce the use of antibiotics for infected wound management. Hence, a versatile hydrogel dressing (rGB/QCS/PDA-PAM) exhibiting skin adaptiveness on dynamic wounds and  mild photothermal antibacterial activity is developed for safe and efficient infected wound treatment. Phenylboronic acid-functionalized graphene (rGB) and oxadiazole-decorated quaternary carboxymethyl chitosan (QCS) are incorporated into a polydopamine-polyacrylamide (PDA-PAM) network with multiple covalent and noncovalent bonds, which conferred the hydrogel with flexible mechanical properties, strong tissue adhesion and excellent self-healing ability on the dynamic wounds. Moreover, the glycocalyx-mimicking phenylboronic acid on the surface of rGB enables the hydrogel to specifically capture bacteria. The enhanced membrane permeability of QCS enhanced bacterial vulnerability to photothermal therapy(PTT), which is demonstrated by efficient mild PTT antibacteria against methicillin-resistant Staphylococcus aureus in vitro and in vivo at temperatures of <49.6 °C. Consequently, the hydrogel demonstrate accelerated tissue regeneration on MRSA-infected wound in vivo, with an intact epidermis, abundant collagen deposition and prominent angiogenesis. Therefore, rGB/QCS/PDA-PAM is a versatile hydrogel dressing exhibiting inherent antibacterial activity and has considerable potential in treating wounds infected with drug-resistant bacteria.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Hydrogels , Anti-Bacterial Agents/pharmacology , Bandages , Wound Healing
13.
ACS Appl Mater Interfaces ; 15(10): 12750-12765, 2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36852940

ABSTRACT

The application of photodynamic therapy (PDT) has attracted remarkable interest in cancer treatment because of the advantages of noninvasiveness and spatiotemporal selectivity. However, the PDT efficiency is considerably limited by photosensitizer (PS) quenching and severe hypoxia in solid tumors. Herein, a kind of near infrared (NIR)-activatable methylene blue (MB) peptide nanocarrier was developed for codelivery of nitric oxide (NO) prodrug JSK, expecting a cascade of reactive oxygen species (ROS) amplification-mediated antitumor PDT. In detail, MB was conjugated to water-soluble polyethylene glycol-polylysine (PEG-PLL) through NIR-photocleavable 10-N-carbamoyl bonds, and the subsequent amphiphilic conjugates (mPEG-PLL-MB) self-assembled into nanoparticles (NPs), which allowed JSK codelivery via π-π stacking interactions. MB in quenched state in mPEG-PLL-MB/JSK NPs could be photoactivated by NIR light locoregionally in a controlled manner due to the photocleavage of carbamoyl bonds. Apart from ROS production, assembly disturbance and even disintegration of mPEG-PLL-MB/JSK occurred along with MB activation that subsequently freed JSK, which was further triggered by intracellularly overexpressed glutathione (GSH) and glutathione S-transferase (GST) to sustain the release of NO. NO then served as a hypoxia relief agent through inhibition of cellular respiration to economize O2, cooperating with MB activation and GSH depletion, which synergistically enabled a cascade of ROS amplification to augment PDT for mitochondrial apoptosis-mediated tumor inhibition in vitro and in vivo. Therefore, this pioneering strategy of cascade amplification of ROS addressed the key issues of PS inactivation, hypoxia resistance, and ROS neutralization in a three-pronged approach, which hold great promise in efficient antitumor PDT.


Subject(s)
Nanoparticles , Neoplasms , Photochemotherapy , Prodrugs , Humans , Reactive Oxygen Species , Methylene Blue/pharmacology , Methylene Blue/chemistry , Nitric Oxide , Prodrugs/pharmacology , Photosensitizing Agents/chemistry , Nanoparticles/chemistry , Neoplasms/drug therapy , Peptides/pharmacology , Hypoxia/drug therapy , Cell Line, Tumor
14.
J Colloid Interface Sci ; 629(Pt B): 65-75, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36152581

ABSTRACT

The "shuttle effect" of lithium polysulfides (LiPSs) leads to loss of active materials and the deterioration of cycle stability, which seriously restricts the practical progress of lithium-sulfur (Li-S) batteries. The diffusion of soluble discharge intermediate is the root cause of the above problems. Herein, we synthesized a porous organic framework material (HUT-8) based on triazine network, the polar groups above the hollow structure can not only adsorb LiPSs through electron donating effect, but also anchored cobalt (II) ions provide a large number of binding sites for the in-situ growth of CoS2. This ensured maximized exposure of catalytic centre and improve their interactions with sulfur redox species under the confinement of mesopores, which can catalytically accelerate capture/diffusion of LiPSs and precipitation/decomposition of Li2S. Based on the synergistic effect of the composite materials, the CoS2-HUT-8/S cathode maintained a capacity of 583 mAh g-1 after 500 cycles at 1 C, and a minimum capacity fading rate of 0.046% per cycle. A freestanding CoS2-HUT-8/S cathode with sulfur loading of 5.2 mg cm-2 delivered a high areal capacity of 4.01 mAh cm-2 under a lean electrolyte, which would provide great potential for the practical progress of Li-S batteries.

15.
Chemistry ; 29(1): e202202787, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36196504

ABSTRACT

The development of new vinylene-linked covalent organic frameworks (COFs) with special ionic structure and high stability is challenging. Herein, we report a facile, general method for constructing ionic vinylene-linked thiopyrylium-based COFs from 2,4,6-trimethylpyrylium tetrafluoroborate and other common reagents by means of acid-catalyzed Aldol condensation. Besides, pyrylium-, and pyridinium-based COFs also can be prepared from the same monomer under slightly different reaction conditions. The COFs exhibited uniform nanofibrous morphologies with excellent crystallinities, special ionic structures, well-defined nanochannels, and high specific surface areas.

16.
Polymers (Basel) ; 14(21)2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36365667

ABSTRACT

Boron nitride nanosheets (BNNSs) show excellent thermal, electrical, optical, and mechanical properties. They are often used as fillers in polymers to prepare thermally conductive composites, which are used in the production of materials for thermal management, such as electronic packaging. Aside from the van der Waals force, there are some ionic bond forces between hexagonal boron nitride (h-BN) layers that result in high energy consumption and make BNNSs easily agglomerate. To overcome this issue, L-lysine (Lys) was first employed as a stripping assistant for preparing graft-functionalized BNNSs via mechanical sand-milling technology, and the obtained Lys@BNNSs can be added into thermoplastic polyurethane (TPU) by solution mixing and hot-pressing methods to prepare thermally conductive composites. This green and scalable method of amino acid-assisted sand-milling can not only exfoliate the bulk h-BN successfully into few-layer BNNSs but also graft Lys onto the surface or edges of BNNSs through Lewis acid-base interaction. Furthermore, benefiting from Lys's highly reactive groups and biocompatibility, the compatibility between functionalized BNNSs and the TPU matrix is significantly enhanced, and the thermal conductivity and mechanical properties of the composite are remarkably increased. When the load of Lys@BNNSs is 3 wt%, the thermal conductivity and tensile strength of the obtained composites are 90% and 16% higher than those of the pure TPU, respectively. With better thermal and mechanical properties, Lys@BNNS/TPU composites can be used as a kind of heat dissipation material and have potential applications in the field of thermal management materials.

17.
ACS Appl Mater Interfaces ; 14(35): 39787-39798, 2022 Sep 07.
Article in English | MEDLINE | ID: mdl-36001127

ABSTRACT

Stimuli-activatable nanomaterials hold significant promise for tumor-specific drug delivery by recognizing the internal or external stimulus. Herein, we reported a dual-responsive and biodegradable polypeptide nanoparticle (PPTP@PTX2 NP) for combinatory chemotherapy and photodynamic therapy (PDT) of breast cancer. The NPs were engineered by encapsulating diselenide bond linked dimeric prodrug of paclitaxel (PTX2) in an intracellular acidity-activatable polypeptide micelle. Specifically, the acid-responsive polypeptide was synthesized by grafting a tetraphenyl porphyrin (TPP) photosensitizer and N,N-diisopropylethylenediamine (DPA) onto the poly(ethylene glycol)-block-poly(glutamic acid) diblock copolymer by the amidation reaction, which self-assembled into micellar NPs and was activated inside the acidic endocytic vesicles to perform PDT. The paclitaxel dimer can be stably loaded into the polypeptide NPs and be restored by PDT inside the tumor cells. The formed PPTP@PTX2 NPs remained inert during blood circulation and passively accumulated in the tumor foci, which could be activated within the endocytic vesicles via acid-triggered protonation of DPA groups to generate fluorescence signal and release PTX2 in 4T1 murine breast tumor cells. Upon 660 nm laser irradiation, the activated NPs carried out PDT via TPP and chemotherapy via PTX to induce apoptosis of 4T1 cells and thereby efficiently inhibited 4T1 tumor growth and prevented metastasis of tumor cells.


Subject(s)
Nanoparticles , Neoplasms , Photochemotherapy , Animals , Cell Line, Tumor , Drug Delivery Systems , Mice , Micelles , Nanoparticles/chemistry , Neoplasms/drug therapy , Paclitaxel , Peptides/pharmacology , Peptides/therapeutic use , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Polymers/chemistry
18.
Macromol Rapid Commun ; 43(11): e2200135, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35365902

ABSTRACT

The development of biomimetic extracellular matrix (ECM) with fibrous structure and complex nonlinear mechanics has been attracting intensive attention over the past decades both in material science and tissue engineering. Polyisocyanopeptide (PIC) hydrogels are a class of fully synthetic materials that can mimic biogels, such as fibrin and collagen, in nearly all aspects, particularly the micron-sized gel network and the strong strain-stiffening behavior in the biological regime. Here, a biomimetic PIC/hydroxyapatite (HA) hybrid composite through an enzymatic biomineralization strategy is constructed. HA biominerals grew on PIC bundles in situ catalyzed by the embedded alkaline phosphatase (ALP), which further crosslinked the gel networks and reinforced the mechanical property of PIC hydrogels. Significantly, PIC/HA composites exhibited ultra-responsive nonlinear mechanics with higher sensitivity to mechanical stress compared with those without biomineralization. As a consequence, the presence of HA can provide cell adhesion sites for PIC gels and induce osteogenic differentiation of pre-osteoblasts by virtue of the changes in mechanical properties. With these outstanding properties, therefore, PIC/HA composites present promising prospects in bone tissue engineering as biomimetic ECM.


Subject(s)
Durapatite , Osteogenesis , Durapatite/chemistry , Hydrogels/chemistry , Osteoblasts , Tissue Engineering , Tissue Scaffolds/chemistry
19.
Colloids Surf B Biointerfaces ; 214: 112469, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35339902

ABSTRACT

The high adhesive property of polydopamine (PDA) has spurred various hydrogels for biological and medical applications. Herein, a dual-catalytic redox system was constructed by using the inner dynamic redox-activity of PDA and free radical initiator ammonium persulfate (APS) to initiate the polymerization of acrylic acid (AA) monomer to obtain Fe-PDA hydrogels within 2 h at room temperature. Fe-PDA NPs functions as both initiator to activate APS to generate free radicals and promotes the formation of the hydrogel and dynamic cross-linking mediator between the polymer chains. The tensile strength and ductility of the obtained hydrogels vary with the content of Fe-PDA NPs. Hydrogel with 0.15 wt% of Fe-PDA NPs has the highest tensile strength (~0.62 MPa) and hydrogel with 0.6 wt% of Fe-PDA NPs has the highest elongation, about ~650%. The introduction of PDA NPs imparts PAA hydrogel with reproducible adhesive properties and self-healing ability. The doped iron ion further endows hydrogel enhanced photothermal properties (up to 160 â„ƒ with 808 nm laser irradiation for 120 s) and conductivity.


Subject(s)
Adhesives , Hydrogels , Indoles , Polymers
20.
Nanotechnology ; 33(22)2022 Mar 08.
Article in English | MEDLINE | ID: mdl-35158345

ABSTRACT

The practical application of lithium-sulfur battery is seriously limited by the loss of active substances and the deterioration of cycle stability caused by the 'shuttle effect' of lithium polysulfides (LiPSs). In this work, graphene oxide (GO) coated covalent organic framework (COF) compound materials were synthesized as sulfur host material in spray-drying process. The polar groups on COF can efficiently adsorb LiPSs through lithiophilic interaction, which can reduce the 'shuttle effect' caused by soluble LiPSs. Besides, GO in the outer layer can wrap discrete sulfur to reduce the loss of active substances, which further improves the cycle stability of the cathode. The COF@GO/S cathode exhibits a high initial specific capacity of 848.4 mAh g-1and retains a capacity of 601.1 mAh g-1after 500 cycles at 1 C counting with a low capacity fading of 0.058% per cycle.

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