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Background Periodontitis is a chronic inflammatory disease in oral cavity owing to bacterial infection. Photothermal therapy (PTT) and photodynamic therapy (PDT) have many advantages for antibacterial treatment. As an excellent photosensitizer, indocyanine green (ICG) shows prominent photothermal and photodynamic performances. However, it is difficult to pass through the negatively charged bacterial cell membrane, thus limiting its antibacterial application for periodontitis treatment. Results In this work, self-assembled nanoparticles containing ICG and polycationic brush were prepared for synergistic PTT and PDT against periodontitis. First, a star-shaped polycationic brush poly(2-(dimethylamino)ethyl methacrylate) (sPDMA) was synthesized via atom transfer radical polymerization (ATRP) of DMA monomer from bromo-substituted β-cyclodextrin initiator (CD-Br). Next, ICG was assembled with sPDMA to prepare ICG-loaded sPDMA (sPDMA@ICG) nanoparticles (NPs) and the physicochemical properties of these NPs were characterized systematically. In vitro antibacterial effects of sPDMA@ICG NPs were investigated in porphyromonas gingivalis (Pg), one of the recognized periodontitis pathogens. A ligature-induced periodontitis model was established in Sprague–Dawley rats for in vivo evaluation of anti-periodontitis effects of sPDMA@ICG NPs. Benefiting from the unique brush-shaped architecture of sPDMA polycation, sPDMA@ICG NPs significantly promoted the adsorption and penetration of ICG into the bacterial cells and showed excellent PTT and PDT performances. Both in vitro and in vivo, sPDMA@ICG NPs exerted antibacterial and anti-periodontitis actions via synergistic PTT and PDT. Conclusions A self-assembled nanosystem containing ICG and polycationic brush has shown promising clinical application for synergistic PTT and PDT against periodontitis. Graphical Abstract

Dentin hypersensitivity (DH) causes considerable discomfort in many patients due to its characteristic symptoms, which primarily arise from exposed dentinal tubules (DTs). DTs also serve as a pathway for bacterial invasion. Therefore, a treatment that both effectively occludes DTs and prevents caries is needed. Polyaspartic acid (Pasp) and carboxymethyl chitosan (CMC) were combined with amorphous calcium phosphate (ACP) to develop PCA. PCA was compared with three polyelectrolyte complexes (PA, CA, PC). Recombinant collagen models assessed the mineralization-promoting effect of PCA, whereas DH models evaluated its ability to occlude DTs. The sealing performance and surface hardness of PCA-treated dentin discs were assessed by airtightness and hardness tests. Antibacterial effects were analyzed using live-dead staining, bacterial adherence assays, and colony-forming unit (CFU) counts. Biocompatibility was evaluated by live-dead cell staining, CCK-8 assays, and hemolysis tests. PCA contains ACP clusters approximately 2 nm in diameter and achieves effective intrafibrillar mineralization within 5 days. PCA completely covers the collagen fibers on the dentin surface and occludes the DTs. The remineralized dentin demonstrates excellent resistance to friction and acid exposure. PCA treatment significantly restores the airtightness and mechanical strength of demineralized dentin. Moreover, PCA exhibits strong antibacterial activity against Streptococcus mutans ( ). Biocompatibility tests confirm favorable safety profiles. This study demonstrates the dual function of PCA in DH management and caries prevention by occluding DTs and providing antibacterial protection, supporting its potential for clinical application.

Chitosan (CH)–carboxymethyl cellulose sodium salt (NaCMC) microcapsules containing paraffin oil were synthesized by complex formation, and crosslinked with glutaraldehyde (GTA). The electrostatic deposition of NaCMC onto the CH-coated paraffin oil emulsion droplets was demonstrated by zeta potential and optical microscopy. The optimal process conditions were identified in terms of pH of the aqueous solution (5.5) and CH/NaCMC mass ratio (1:1). Encapsulation of paraffin oil and microcapsule morphology were analyzed by ATR-FTIR and SEM, respectively. The effect of GTA crosslinking on paraffin oil latent heat was investigated by DSC and combined with the values of encapsulation efficiency and core content, supporting the compact shell formation.

The current global scenario presents us with a growing increase in infections caused by fungi, referred to by specialists in the field as a “silent epidemic”, aggravated by the limited pharmacological arsenal and increasing resistance to this therapy. For this reason, drug repositioning and therapeutic compound combinations are promising strategies to mitigate this serious problem. In this context, this study investigates the antifungal activity of the non-toxic, low-cost and widely available cationic polyelectrolyte Poly(diallyldimethylammonium chloride) (PDDA), in combination with different antifungal drugs: systemic (amphotericin B, AMB), topical (clioquinol, CLIO) and oral (nitroxoline, NTX). For each combination, different drug:PDDA ratios were tested and, through the broth microdilution technique, the minimum inhibitory concentration (MIC) of these drugs in the different ratios against clinically important Candida species strains was determined. Overall, PDDA combinations with the studied drugs demonstrated a significant increase in drug activity against most strains, reaching MIC reductions of up to 512 fold for the fluconazole resistant Candida krusei (Pichia kudriavzevii). In particular, the AMB-PDDA combination 1:99 was highly effective against AMB-resistant strains, demonstrating the excellent profile of PDDA as an adjuvant/association in novel antifungal formulations with outdated conventional drugs.

Local gene delivery systems utilizing RNA interference technology are a promising approach for therapeutic applications where site-specific release of agents is desired. Polyelectrolyte multilayers (PEMs) can be constructed using the layer-by-layer (LbL) technique and serve as a depot for bioactive substances, which can then be released in a controlled manner. Multilayers of hyaluronic acid/poly(ethylenimine) HA/PEI were built up with different numbers of bilayers and PEI-siRNA particles were embedded in bioactive layers for gene silencing. The increase of the bilayers and the release of siRNA particles were demonstrated by fluorescence intensity measurement with a fluorescence reader. Two different LbL techniques were tested for the reduction of ICAM-1 expression in EA.hy926: PEM build-up by dipping or drying steps, respectively. Herein, the drying technique of the bioactive layers with ICAM siRNA mediated a significant reduction of the ICAM-1 expression from 3 to 24 bilayers. The fluorescent siRNA release study and the re-culturing of the HA/PEI films demonstrated a release of the transfection particles within the first hour. The advantage of dried built-up PEMs compared to a dried monolayer of PEI-siRNA particles with the same siRNA concentration was a significant higher amount of viable cells.

Background The biofunctionalization of titanium implants for high osteogenic ability is a promising approach for the development of advanced implants to promote osseointegration, especially in compromised bone conditions. In this study, polyelectrolyte multilayers (PEMs) were fabricated using the layer-by-layer approach with a chitosan-miRNA (CS-miRNA) complex and sodium hyaluronate (HA) as the positively and negatively charged polyelectrolytes on microarc-oxidized (MAO) Ti surfaces via silane-glutaraldehyde coupling. Methods Dynamic contact angle and scanning electron microscopy measurements were conducted to monitor the layer accumulation. RiboGreen was used to quantify the miRNA loading and release profile in phosphate-buffered saline. The in vitro transfection efficiency and the cytotoxicity were investigated after seeding mesenchymal stem cells (MSCs) on the CS-antimiR-138/HA PEM-functionalized microporous Ti surface. The in vitro osteogenic differentiation of the MSCs and the in vivo osseointegration were also evaluated. Results The surface wettability alternately changed during the formation of PEMs. The CS-miRNA nanoparticles were distributed evenly across the MAO surface. The miRNA loading increased with increasing bilayer number. More importantly, a sustained miRNA release was obtained over a timeframe of approximately 2 weeks. In vitro transfection revealed that the CS-antimiR-138 nanoparticles were taken up efficiently by the cells and caused significant knockdown of miR-138 without showing significant cytotoxicity. The CS-antimiR-138/HA PEM surface enhanced the osteogenic differentiation of MSCs in terms of enhanced alkaline phosphatase, collagen production and extracellular matrix mineralization. Substantially enhanced in vivo osseointegration was observed in the rat model. Conclusions The findings demonstrated that the novel CS-antimiR-138/HA PEM-functionalized microporous Ti implant exhibited sustained release of CS-antimiR-138, and notably enhanced the in vitro osteogenic differentiation of MSCs and in vivo osseointegration. This novel miRNA-functionalized Ti implant may be used in the clinical setting to allow for more effective and robust osseointegration.

To overcome the high relapse rate of multiple myeloma (MM), a drug delivery coating for functionalization of bone substitution materials (BSM) is reported based on adhesive, catechol-containing and stimuli-responsive polyelectrolyte complexes (PECs). This system is designed to deliver the MM drug bortezomib (BZM) directly to the anatomical site of action. To establish a gradual BZM release, the naturally occurring caffeic acid (CA) is coupled oxidatively to form poly(caffeic acid) (PCA), which is used as a polyanion for complexation. The catechol functionalities within the PCA are particularly suitable to form esters with the boronic acid group of the BZM, which are then cleaved in the body fluid to administer the drug. To achieve a more thorough control of the release, the thermoresponsive poly(N-isoproplyacrylamide-co-dimethylaminoethylmethacrylate) (P(NIPAM-co-DMAEMA)) was used as a polycation. Using turbidity measurements, it was proven that the lower critical solution temperature (LCST) character of this polymer was transferred to the PECs. Further special temperature dependent attenuated total reflection infrared spectroscopy (ATR-FTIR) showed that coatings formed by PEC immobilization exhibit a similar thermoresponsive performance. By loading the coatings with BZM and studying the release in a model system, via UV/Vis it was observed, that both aims, the retardation and the stimuli control of the release, were achieved.

Meat is one of the most challenging food products in the context of maintaining quality and safety. The aim of this work was to improve the quality of raw/cooked meat by coating it with sodium alginate (A), chitosan (C), and sodium alginate-chitosan polyelectrolyte complex (PEC) hydrosols. Antioxidant properties of A, C, and PEC hydrosols were determined. Subsequently, total antioxidant capacity (TAC), sensory quality of raw/cooked pork coated with experimental hydrosols, and antimicrobial efficiency of those hydrosols on the surface microbiota were analysed. Application analyses of hydrosol were performed during 0, 7, and 14 days of refrigerated storage in MAP (modified atmosphere packaging). Ferric reducing antioxidant power (FRAP) and (2,2-diphenyll-picrylhydrazyl (DPPH) analysis confirmed the antioxidant properties of A, C, and PEC. Sample C (1.0%) was characterized by the highest DPPH value (174.67 μM Trolox/mL) of all variants. PEC samples consisted of A 0.3%/C 1.0% and A 0.6%/C 1.0% were characterized by the greatest FRAP value (~7.21 μM Fe2+/mL) of all variants. TAC losses caused by thermal treatment of meat were reduced by 45% by coating meat with experimental hydrosols. Application of PEC on the meat surface resulted in reducing the total number of micro-organisms, psychrotrophs, and lactic acid bacteria by about 61%, and yeast and molds by about 45% compared to control after a two-week storage.

Cerium oxide nanoparticles (nanoceria) are believed to be the most versatile nanozyme, showing great promise for biomedical applications. At the same time, the controlled intracellular delivery of nanoceria remains an unresolved problem. Here, we have demonstrated the radioprotective effect of polyelectrolyte microcapsules modified with cerium oxide nanoparticles, which provide controlled loading and intracellular release. The optimal (both safe and uptake efficient) concentrations of ceria-containing microcapsules for human mesenchymal stem cells range from 1:10 to 1:20 cell-to-capsules ratio. We have revealed the molecular mechanisms of nanoceria radioprotective action on mesenchymal stem cells by assessing the level of intracellular reactive oxygen species (ROS), as well as by a detailed 96-genes expression analysis, featuring genes responsible for oxidative stress, mitochondrial metabolism, apoptosis, inflammation etc. Hybrid ceria-containing microcapsules have been shown to provide an indirect genoprotective effect, reducing the number of cytogenetic damages in irradiated cells. These findings give new insight into cerium oxide nanoparticles’ protective action for living beings against ionising radiation.

The immunotropic activity of polyelectrolyte complexes (PEC) of κ-carrageenan (κ-CGN) and chitosan (CH) of various compositions was assessed in comparison with the initial polysaccharides in comparable doses. For this, two soluble forms of PEC, with an excess of CH (CH:CGN mass ratios of 10:1) and with an excess of CGN (CH: CGN mass ratios of 1:10) were prepared. The ability of PEC to scavenge NO depended on the content of the κ-CGN in the PEC. The ability of the PEC to induce the synthesis of pro-inflammatory (tumor necrosis factor-α (TNF-α)) and anti-inflammatory (interleukine-10 (IL-10)) cytokines in peripheral blood mononuclear cell was determined by the activity of the initial κ-CGN, regardless of their composition. The anti-inflammatory activity of PEC and the initial compounds was studied using test of histamine-, concanavalin A-, and sheep erythrocyte immunization-induced inflammation in mice. The highest activity of PEC, as well as the initial polysaccharides κ-CGN and CH, was observed in a histamine-induced exudative inflammation, directly related to the activation of phagocytic cells, i.e., macrophages and neutrophils.