Crosslinking Process Research Articles

Intelligent responsive nanogels: New Horizons in cancer therapy.

Biologically engineered nanogels formed through sophisticated intramolecular crosslinking processes represent the forefront of next-generation drug delivery systems. These innovative systems offer many advantages, like adjustable size, satisfactory biocompatibility, and minimal toxicity. Their unique attributes facilitate deep penetration and long-term retention of drugs in tumors, effectively enhancing the anti-tumor effects. Nonetheless, the rapid disintegration of nanogels and the subsequent triggering of drug release at the tumor site pose significant challenges in achieving more effective and precise tumor treatments. Therefore, increasing research has been dedicated to exploring stimulus-responsive nanogels for enhancing tumor therapy. This review aims to encapsulate the research advancements in emerging stimulus-responsive antitumor nanogels. Firstly, a detailed exposition is provided on various endogenous stimulus-responsive nanogels, encompassing factors such as pH, hypoxia, enzymes, reactive oxygen species (ROS), and glutathione (GSH). Secondly, various nanogels triggered by exogenous stimuli such as light, ultrasound, temperature, and magnetic fields are elaborately presented. Furthermore, nanogels with multifaceted stimulus-responsive properties are also skillfully designed. Finally, the future directions, application prospects, and challenges of intelligent responsive nanogels in cancer treatment are highlighted.

Multifunctional fructose-crosslinked fibroin film with a developed β-sheet structure for advanced food packaging

The replacement of petroleum-based plastic packaging with sustainable biopolymer-based materials is still a significant challenge. In the current study, we present a novel approach to impart the multifunctionality of fibroin film through a facile fructose-mediated crosslinking process. By generating a synergistic effect by inducing the transition to β-sheet structure and introducing covalent bonds within the fibroin chain, we effectively controlled the physicochemical characteristics of fibroin film, resulting in exceptional mechanical properties surpassing previous fibroin-based films. The fructose-crosslinked fibroin films exhibited exceptional mechanical properties, including a toughness of 3767.73 kPa and a Young's modulus of 3.06 GPa, surpassing previously reported fibroin-based films. The films also demonstrated excellent optical properties, with 98.49 % transmittance at 700 nm. Moisture stability was significantly enhanced, as the incorporation of fructose reduced water solubility by increasing β-sheet crystallinity and improved bulk water retention through its hygroscopic properties. Additionally, Maillard reaction products formed during crosslinking provided superior ultraviolet shielding and enhanced antioxidant properties, making the films ideal for active food packaging. The multifunctionality of fructose-crosslinked fibroin film significantly improves food storage stability when used in sustainable and eco-friendly food packaging applications. This high-performance fructose-mediated crosslinked fibroin film with a developed β-sheet structure emerges as a promising alternative to petroleum-based materials, offering a sustainable solution for the advanced packaging field.

Lightweight and superamphiphobic silanized cellulose–silica aerogels on green flexible thermal substrates

Silica aerogel materials, a wonder material to change the world, really do have fantastic properties and their potential is huge, such as excellent and unique light, heat, fluid, and ion performance, but suffers from vulnerability to external damage, leading to cracks within the material, followed by fracture and flacking, and thus loss of thermal insulation capability. Here, we have manufactured lightweight porous silanized cellulose-silica aerogels (SCSA) by a colloidal self-assembly crosslinking process using silica aerogel powder starting material in dilute nanocellulose slurry. SCSA exhibits a wide range of advantages, including ultradurable thermomechanical stability and robust superamphiphobicity up to 160.2° WCA and 159.7° OCA, excellent humidity tolerance as low as 28.4 mW m−1 K−1 at 30 ∼ 90 % relative humidity, superelasticity up to 90 %, and near-zero plastic deformation, as well as the ultralow thermal conductivity of 19.2 mW m−1 K−1 at 25 °C, and 38.6 mW m−1 K−1 at 500 °C. SCSA has excellent superamphiphobicity, environmental friendliness, and thermal superinsulation, which can address the problem of homogeneous heating of electronic products in confined spaces and improve the performance and service life of electronic products by providing thermal protection for less heat-resistant components with poor heat resistance.

Waste management of straw to manufacture biochar: An alternative reinforcing filler for natural rubber biocomposites

To achieve climate neutrality, alternative processes and materials should be proposed to replace those currently in use, which excessively burden the environment. Fossil fuels are non-renewable, and their resources are slowly being depleted, leading to increased prices.The aim of this work was to determine the potential of using agro-industrial residues in the form of oat straw for the production of biochar and its utilization as a filler in natural rubber biocomposites. The process of pyrolysis of plant material was used to obtain biochar with a high carbon content and a characteristic structure, which can affect selected rubber properties. The influence of the applied temperature of the pyrolysis process on the properties of the filler was determined. In this work, analysis techniques were used to enable the evaluation of both filler activity and specific properties of the final vulcanizates. The course of straw pyrolysis process, the carbon content in the fillers, and the size distribution of the bio-additive were examined. The structural, morphological, dispersion, processing, and functional properties of the compositions were examined. The reference in assessing the impact of the produced bio-additive on the properties of the product were composites filled with a commercial carbon black.The conducted research proved that the pyrolysis of straw at a temperature of 600°C was as effective as that carried out at a higher temperature, with comparable weight loss for both samples. The increase in torque was the highest in the case of biochar samples (torque gain 4,4-6,5 dNm), indicating greater intensity of the cross-linking process after the use of this type of additive. This was also confirmed by differential scanning calorimetry. Moreover, the obtained biocomposites were characterized by much higher strength parameters (tensile strength 18,3-21,3MPa) than conventional composites. Unfortunately, vulcanizates containing biochar as a filler exhibited poor resistance to thermo-oxidative aging (aging factor 0,24-0,54).

Analysis of Insulation Properties for High Voltage Applications – A Review

Four popular plastic polymers (LLDPE, XLPE, LDPE and HDPE) that are frequently utilised in high voltage applications are thoroughly examined in the review. It highlights how crucial it is to choose the right insulating material based on your needs. HDPE is perfect for pipes and packaging due to its density and crystallinity. Because of its superior mechanical and thermal properties due to the cross-linking process, XLPE is the material of choice for electrical insulation. The low density, impact resistance and flexibility of LDPE are well known. The essay also examines initiatives to improve these materials, such as the use of nanofillers for XLPE in HVDC cable applications and the addition of alumina nanoparticles to HDPE to boost its dielectric qualities. In conclusion, XLPE excels in thermal stability and electrical insulation, HDPE in toughness and chemical resistance and LDPE in flexibility and impact resistance. The best material to use depends on the needs of the high voltage application. Overall, the essay offers a complete analysis of the characteristics and possible applications of LLDPE, XLPE, LDPE and HDPE in high voltage insulation.

Fe, N-CQDs triggered the fabrication of alginate encapsulated g-C3N4 hydrogel for efficient photocatalytic activation of PMS and antibiotic degradation

Carbon dots (CDs) mediated g-C3N4 (CN) is a promising visible-light-driven semiconductor in catalyzing peroxymonosulfate (PMS) for aqueous contaminants remediation. However, the poor dispersibility of powered catalyst and its challenging recyclability impede their broader application. Herein, we embedded FeN bridge within the g-C3N4 framework and immobilized g-C3N4 gel beads (CA/FNCCN) through a 3D cross-linking process with sodium alginate. Alginate can serve as a stabilizing carrier, preserving the crystalline structure of FNCCN through the formation of H bonds between alginate and FNCCN. The resulting beads displayed significantly improved photo-electrochemical performance, along with greatly enhanced adsorption capacity and catalytic activity toward Sulfamethoxazole (SMX). The catalytic efficiency of CA/FNCCN was markedly increased as compared to non-immobilized FNCCN due to reduced photo-carrier recombination and accelerated electron transport. CA/FNCCN-1 can degrade 99.18 % of SMX within 40 mins, with noteworthy reduced Fe leaching. The primary active species in the system were 1O2 and h+, and the direct electron transfer between PMS and SMX mediated by alginate also contributed to the removal of SMX. Additionally, the degradation pathway of SMX was elucidated through LC-MS and DFT calculations. Simultaneously, FNCCN integrated alginate hydrogel can remain active without decay after 10 cycles.

Granular Nanofiber-Hydrogel Composite-Programmed Regenerative Inflammation and Adipose Tissue Formation.

The interplay between biomaterials and host immune responses critically determines outcomes in tissue restoration. Recent studies suggest that physicochemical properties of materials can dictate pro-regenerative versus pro-fibrotic responses and have begun to define the key immune cell types and signals governing these divergent effects. This emerging understanding enables the engineering of regenerative biomaterials capable of functional restoration in situ. An injectable nanofiber-hydrogel composite (NHC) microparticles are designed and constructed from cross-linked electrospun collagen nanofiber fragments surface-bonded to the hyaluronic acid hydrogel network via covalent conjugation during the cross-linking process. The collagen nanofiber fragments, acting as the structural reinforcement component, increased the overall storage modulus of the NHC to a level comparable to native soft tissues while maintaining a sufficiently high degree of porosity of the hydrogel phase to allow host cell infiltration following subcutaneous injection of the NHC microparticles. More importantly, the NHC promoted macrophage/monocyte infiltration, migration, and spreading, sustained cell recruitment over time, and enhanced the proangiogenic effect and recruitment of PDGFRα+ perivascular progenitor cells, leading to extensive adipose tissue remodeling. This study demonstrates the regenerative potential of the injectable NHC microgels as an off-the-shelf solution for devastating soft tissue losses.

Ultra-high molecular weight poly(vinylamine) polyelectrolyte-functionalized 3D graphene oxide composite aerogels with pH-adaptability for the multi-selective adsorption of organic pollutants

Developing new adsorbents with multi-selectivity is essential for achieving efficient adsorption of various organic pollutants in wastewater. Hence, a novel ultra-high molecular weight poly(vinylamine) (PVAm) polyelectrolyte-functionalized graphene oxide (GO) composite aerogel (CA) adsorbent (PVAm@GO-CA) was successfully prepared via rapid electrostatic assembly and in-situ covalent cross-linking processes. The resulting PVAm@GO-CA exhibits a well-defined 3D porous structure, large specific surface area, and abundant primary amino groups (–NH2), providing numerous adsorption sites. Experimental results demonstrate that the –NH2 groups in PVAm@GO-CA exhibit varying degrees of protonation at different pH levels, allowing for precise controlof the adsorption selectivity for specific organic pollutants with different electrical charges. The results showed that the prepared PVAm@GO-CA is highly efficient for multi-selective adsorption of the anionic dye methyl orange (MO) at pH < 3, the partially ionized 1-naphthol at pH = 6–8, and the cationic dye methylene blue (MB) at pH > 9. The maximum removal capacities for MO, 1-naphthol and MB, as calculated by the Langmuir model, were 796.8, 456.6 and 612.5 mg/g under optimal pH conditions in a mixed system, respectively. The adsorption mechanism of PVAm@GO-CA involves hydrogen bonding, electrostatic interactions, π-π interactions, and nucleophilic/electrophilic interactions with various organic pollutants. This studypaves the way for the preparation ofPVAm@GO-CA withacontrolled surface microenvironment, enablingefficient multi-selective adsorption of multiple organic pollutants through pH regulation.

Recycling the sediment of cotton spinning effluent for rigid polyurethane foams

Sediment from the effluent of cotton spinning industry was valorized as the renewable bio-based polyols substitute for the rigid polyurethane (RPUFs), targeting to generate the economic and environmental benefits. Before reaction with the isocyanate, the sediment was functionalized by hydroxymethylation, in order to increase the density of the active hydroxyl groups for higher reactivity. The structural characterization results of the functionalized sediment indicated the material exhibited narrow molecular weight distribution, high hydroxyl groups content, and highly aromatic skeleton, which can be qualified as the renewable polyols for the RPUFs. In the crosslinking process, the effect of the polyols substitute rate of the sediments on the physio-chemical properties and the thermo-resistant performances of the resulting RPUFs was investigated. Specifically, in the group with 30 wt% of polyols substitution, the received foam exhibited comprehensive superiorities in compressive strength (0.58 MPa), apparent density (58 kg m−3), and thermo-conductivity (0.032 W m−1 K−1). Attractively, the RPUFs also exhibited good flame retardancy. The burning time can be extended by 30 % compared to the control group that without the sediment's substitution. Moreover, the RPUF also possessed good degradability, allowing for harmless recycling. The current work provided a potential route for the valorization of the hazardous waste effluent from the cotton spinning industry.

Green and sustainable metal-reinforced bamboo composites with high self-bonding performances

Although the metallization of wood and bamboo has been successfully achieved, challenges such as low efficiency, high costs, and environmental pollution caused by liquid chemical wastes have impeded its widespread adoption in manufacturing. This study presents a novel approach to fabricating metal-reinforced bamboo composite (MRBC) with exceptional performances, utilizing bamboo residues and nano-CuO without use of adhesives. The impact of raw material characteristics, including moisture content of bamboo powder and the amount of nano-CuO additive, on functional properties such as water resistance, flame retardancy and smoke suppression of MRBC was investigated. Also, the forming mechanism of MRBC was elucidated through examination of its microstructure, chemical composition, and thermal stability. Results indicated that the MRBC containing 20 wt% nano-CuO exhibited a high modulus of rupture (MOR) of 54 MPa, an impressive modulus of elasticity (MOE) of 9.3 GPa, a notable surface hardness of 44.4 kgf/mm, and low 24 h water absorption-thickness swelling of 6.5 %, all significantly surpassing those observed in conventional panels. The MRBC exhibited a tightly wrapped, adhered, and cross-linked process under high temperature and pressure conditions, facilitated by multiple synergistic effects such as lignin melting, hydrogen bond networking, physical structure entanglement, and material redox reaction, which contributed to a dense intertwined and consolidated structure. The MRBC demonstrated exceptional structural integrity throughout the combustion process, effectively mitigating potential damage caused by structural collapse due to the incorporation of nano-CuO, which also successfully suppressed smoke and toxic CO gas emissions during combustion. The MRBC showcased advantages of environmental friendliness, water resistance, high strength, flame retardancy and smoke suppression. These attributes position it as an optimal substitute for conventional panels and make it suitable for replacing metals in specific applications. Thus, it demonstrates significant market potential and promising prospects for sustainable development.

Cinnamon oil value addition in natural rubber latex‐organic peroxide vulcanization system

AbstractNatural rubber is a sustainable material which plays a vital role in a wide variety of applications. Value additions to this natural material enhance its horizons of utilization and encompass multiple advantages. This endeavor focuses on elevating the properties of the natural rubber latex (NRL)‐dicumyl peroxide vulcanization system with the utilization of cinnamon oil (CIN‐OIL). CIN‐OIL was characterized by GCMS, FTIR, and UV–Vis. The FTIR and TGA have confirmed the incorporation of the CIN‐OIL into the NRL. Swelling studies confirmed that the addition of CIN‐OIL has not interfered with the process of peroxy crosslinking. The adhesive peel test and facial tissue test clearly concluded that CIN‐OIL has reduced the initial tackiness of the material which is apparent in peroxy NR vulcanizates. Tear strength and modulus values were increased with CIN‐OIL due to the formation of physical crosslinking. Weathering tests confirmed the higher degradability of the CIN‐OIL‐added NRL samples. Furthermore, films were tested positive for antibacterial activity against both gram‐positive and gram‐negative bacteria. Along with the enhanced degradability, antibacterial activity, reduced initial tackiness, and enhanced mechanical properties, CIN‐OIL in NRL has enriched its qualities.

Constructing a multifunctional reactive MXene-based additive for micro-crosslinking polyurea elastomer to achieve superior mechanical properties and enhanced fire safety

The widespread application of polyurea (PUA) in protective coatings typically requires excellent flame retardancy due to real-world usage scenarios. However, the addition of flame retardant additives often compromises the material’s mechanical properties. In this study, a multifunctional reactive additive, MX-SP-NH2, was creatively prepared by covalently grafting spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride (SPDPC) onto MXene (Ti3C2Tx) surfaces, followed by the introduction of 1,3-propanediamine (PDA) by the reaction with SPDPC. MX-SP-NH2 was then incorporated into PUA, participating in its crosslinking process and significantly enhancing both its mechanical strength and flame retardancy. Compared to the control PUA sample, the micro-crosslinked PUA sample with just 1.0 wt% MX-SP-NH2 demonstrated a 184.3% increase in tensile strength, a 126.1% increase in elongation at break, and a 436.3% increase in toughness. The flammability characterization revealed that the peak heat release rate, peak smoke production rate, and peak CO production rate were reduced by 31.7%, 28.9%, and 61.5%, respectively, indicating a substantial improvement in fire safety. Additionally, the flame retardant PUA-based flexible strain sensors demonstrated stable electrical signal responsiveness. This work has opened up new potential applications of PUA in flexible electronics.

Double-crosslinked dECM bioink to print a self-sustaining 3D multi-layered aortic-like construct

Cardiovascular disease is the leading cause of death worldwide, with related mortality increasing from 12.1 million to 18.6 million in the past 30 years.To address the supply limitation of autologous vascular grafts and overcome the limits of current treatment options, 3D bioprinting techniques have been investigated.This study aimed at introducing a self-supporting and multi-layered 3D bioprinted construct as a promising alternative for large-blood vessel replacement. To this end, we developed an alginate-gelatin bioink enriched with decellularized extracellular matrix (dECM) of porcine aorta combined with a two-step crosslinking process. We investigated the feasibility of achieving structural stability and shape fidelity of the bioprinted construct over time through rheological characterization, printability tests, and degradation tests.According to the results of rheology and printability tests, dECM-enriched bioink combined with the double-crosslinking process (internal and external crosslink) showed good printability and high shape fidelity, withstanding more than 35 layers without the need for support. Moreover, the bioprinted construct preserved its structural stability over time, retaining a wall thickness comparable to that of the native aorta. Finally, immortalized mouse fibroblasts embedded in the bioink were well adhered to the bioink and alive over time. The double-crosslinked bioink represents an impactful strategy to produce an alternative conduit with the native hierarchical structure of the large blood vessels.

Macromolecular Function Emerging from Intramolecular Peptide Stapling of Synthetic Polymers.

Protein function results from the precise folding of polypeptides into bespoke architectures. Taking inspiration from nature, the field of single-chain nanoparticles (SCNPs), intramolecularly crosslinked synthetic polymers, emerged. In contrast to nature, the function of SCNPs is generally defined by the parent polymer or the applied crosslinker, rather than by the crosslinking process itself. This work explores the cyanopyridine-aminothiol click reaction to crosslink peptide-decorated polymers intra-macromolecularly to endow the resulting SCNPs with emerging functionality, resulting from the conversion of N-terminal cysteine units into pyridine-thiazolines. Dimethylacrylamide based polymers with different cysteine-terminated amino acid sequences tethered to their sidechains are investigated (P1 (C),P2 (GDHC),P3 (GDSC)) and intramolecularly crosslinked into SCNPs. Since the deprotection of the parent polymers yields disulfide-based SCNPs, a direct comparison between disulfide and pyridine-thiazolines crosslinked SCNPs is possible. This comparison revealed two emerging properties of the pyridine-thiazoline crosslinked SCNPs: 1) The formation of pyridine-thiazolines gave rise to metal binding sites within the SCNP, which complexed iron. 2) Depending on the peptide sequence in the precursor polymer, the hydrolytic activity of the peptide sequences is either increased (GDHC) or decreased (GDSC) uponpyridine-thiazoline formation compared to identical SCNPs based on disulfide crosslinks.

Preparation and Evaluation of Metformin Microspheres by Ionotropic Gelation Method

The purpose of this study was to formulate metformin microsphere in order to lessen its undesirable effects. To prepare metformin microspheres, the ionotropic gelation technique was used. In this process, two ionic components interact under specific circumstances. There needs to be a polymer in at least one of these two ionic components. Microspheres are formed by the simple interaction of an ionic polymer with an oppositely charged ion. In this procedure, the polymers employed were sodium alginate and chitosan; calcium chloride was used for the crosslinking process. Various parameters like particle size, Percentage yield, swelling index, Drug entrapment efficiency, Drug release study (In- vitro) and drug release kinetics studies were performed. From the experimental data it has been shown that chitosan and calcium chloride plays important role for variation of characteristic parameters of microspheres.

Bio-sourced tartaric acid-derived tartarimides as diol counterparts towards renewable polyurethanes

The depletion of petroleum-based fossil resources and ever-increasing environmental problems are serious issues in the production of polymeric materials. An increasingly important approach is to obtain the building blocks used in the production of these materials from renewable sources of natural origin. In the present study, bio-sourced tartaric acid-based tartarimides were evaluated as monomeric diol compounds to synthesize polyurethane polymers. Structurally diverse tartarimides were conveniently obtained from the condensation reactions of tartaric acid with various primary amine compounds. The diol structure of the generated tartarimides allowed to access polyurethanes along with the polymerizations of diisocyanate monomers. Copolymers in the range of 22.9 kDa to 29.3 kDa molecular weights were obtained with moderately high total monomer conversions (up to 96%). Depending on the tartarimide and diisocyanate monomers employed during polymerization, copolymers with different physical and thermal properties were generated. By utilizing tartarimides carrying furan and alkene functionalities, side chain reactive polyurethanes were synthesized. These reactive polymers were evaluated in post-polymerization modification and crosslinking processes by using radical thiol-ene and Diels-Alder based click reactions. The results obtained in this study demonstrated that the bio-sourced tartarimides could provide a convenient access to structurally tailorable polyurethane polymers that are important materials in various applications.

Ionically assembled hemostatic powders with rapid self-gelation, strong acid resistance, and on-demand removability for upper gastrointestinal bleeding.

Upper gastrointestinal bleeding (UGIB) is bleeding in the upper part of the gastrointestinal tract with an acidic and dynamic environment that limits the application of conventional hemostatic materials. This study focuses on the development of N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride/phytic acid (HTCC/PA, HP) powders with fast hemostatic capability and strong acid resistance, for potential applications in managing UGIB. Upon contact with liquids within 5 seconds, HP powders rapidly transform into hydrogels, forming ionic networks through electrostatic interactions. The ionic crosslinking process facilitates the HP powders with high blood absorption (3.4 times of self-weight), sufficient tissue adhesion (5.2 and 6.1 kPa on porcine skin and stomach, respectively), and hemostasis (within 15 seconds for in vitro clotting). Interestingly, the PA imparts the HP powders with strong acid resistance (69.8% mass remaining after 10 days of incubation at pH 1) and on-demand removable sealing while HTCC contributes to fast hemostasis and good wet adhesion. Moreover, the HP powders show good biocompatibility and promote wound healing. Therefore, these characteristics highlight the promising clinical potential of HP powders for effectively managing UGIB.

Molecular insights of DGEBA/MeTHPA three-dimensional resin network from design to heat transfer mechanism: Dynamic simulation and experimental research

The epoxy resin composed of bisphenol A diglycidyl ether (DGEBA) and methyl tetrahydrophthalic anhydride (MeTHPA) has been found to enhance its thermal conductivity by increasing its molecular weight and crosslinking density. This was achieved through experiments and all-atom molecular dynamics simulations. Molecular dynamics was employed to calculate the root-mean-square displacement, free volume fraction, potential energy, density, and quantity of hydrogen bonds. The results showed the influence of molecular weight and crosslinking density on the system's thermal conductivity. The results showed that the high molecular weight epoxy resin system exhibited high thermal conductivity at elevated crosslinking densities. During the crosslinking process, the epoxy resin's thermal conductivity increased, starting with the center portion weakening and then strengthening. In addition, a simulation-verified free volume was found to have an inversely proportional connection with thermal conductivity. This study explored the thermal conductivity mechanism of epoxy resin by analyzing the structural changes at the micro level and correlating them with the changes in thermal conductivity at the macro level to enhance guidance for industrial production and practical application.

The role of cross-linkers in the performance of anion exchange membrane for fuel cell applications

Anion exchange membranes (AEMs) with high OH- conductivity, good alkaline stability, and dimensional stability are still challenges for AEM fuel cells to be used in practice. In this study, high-performance cross-linked AEMs are developed. To construct the hydrophilic ionic channels, a series of polysulfone-based cross-linked AEMs were prepared utilizing the DABDA cation and two distinct cross-linkers (one with ether and one without ether). The cross-linking process enhanced aggregation of ion clusters, which resulted in the formation of ion-conductive channels and phase-separated hydrophilic/hydrophobic morphology, as well as enhancing the dimensional stability of the AEMs. The produced AEMs demonstrated good conductivity relative to their swelling ratio at 70 °C, and high conductivity in the range of 19.6–46.7 mS/cm between 25 and 70 °C. Additionally, the cross-linked AEMs revealed enhanced alkaline, mechanical and thermal stability. This work presents a promising strategy for developing high-efficiency AEMs for fuel cells.

Multifunctional sericin-based biomineralized nanoplatforms with immunomodulatory and angio/osteo-genic activity for accelerated bone regeneration in periodontitis

Periodontitis is a chronic inflammation caused by dental plaque. It is characterized by the accumulation of excessive reactive oxygen species (ROS) and inflammatory mediators in the periodontal area. This affects the function of host cells, activates osteoclasts, and destroys periodontal tissue. Treatments such as local debridement or antibiotic therapy for ameliorating the overactive inflammatory microenvironment and repairing periodontal tissues are challenging. This paper reports multifunctional nanoplatforms (Se-CuSrHA@EGCG) based on sericin with ROS-scavenging, immunomodulatory, angiogenic, and osteogenic capabilities. The natural protein sericin, derived from silk cocoons, is used in water/oil emulsification and cross-linking processes to create sericin nanoparticles (Se NPs). Numerous binding sites are present on the surface of Se NPs. Ion-doped hydroxyapatite nanoparticles (Se-CuSrHA NPs) can be constructed using the force between positive and negative charges. After mineralization, an antioxidant coating is formed on the surface using polyethyleneimine (PEI)/epigallocatechin gallate (EGCG). Research conducted both in vitro and in vivo demonstrates that Se-CuSrHA@EGCG NPs can efficiently scavenge ROS, regulate macrophage polarization, increase the secretion of anti-inflammatory cytokines, and balance the immune microenvironment. In addition, Se-CuSrHA@EGCG stimulates angiogenesis, inhibits osteoclasts, and accelerates periodontal tissue repair. Therefore, this is a preferable strategy to accelerate bone regeneration in patients with periodontitis.