Release Of Tetracycline Research Articles

Sustainable di-functional stimuli-responsive imprinted nanozymes for reversible colorimetric sensing of tetracycline

Regenerable nanozymes with high catalytic specificity and sustainability may serve as substitutes for naturally occurring enzymes, but their application is hindered by inadequate and nonselective catalytic activity. In this study, we constructed a photo-responsive molecularly imprinted layer on the Fe3O4 nanozyme surface (P-MIPs) using an ATRP method and obtained high-specificity reversible colorimetric sensing of tetracycline (TC). Due to the photo-responsive properties of P-MIPs, the imprinted nanozyme undergoes reversible release and uptake of TC under alternating irradiation at 365/440 nm based on the photo-regulated conformational transformation of the 4-[(4-methacryloyloxy)phenylazo] benzenesulfonic acid (MAPASA) at the polymer receptor sites, which may be confirmed by calculating the electron densities of the trans-/cis-MAPASA forms. Simultaneously, these processes can be visualized through the change in the color of the substrates. Highly specific P-MIPs-based nanozyme also exhibit adequate stability and sustainable catalytic activity after multiple cycles. This method can be used to achieve nanozymes with high selectivity for the enrichment, separation, and detection of hazardous substances and contribute to material sustainability.

On-Demand Removable Chitosan Based Self-Healing and Antibacterial Hydrogel for Delivery of Tetracycline and Curcumin As Potential Wound Dressing Material.

Wound care is a flourishing branch of healthcare wherein a great amount of research is devoted to develop competent wound dressings. Safe, cost-effective, and biocompatible dressings aid in wound healing without inflicting external trauma and subsequent scar formation. Toward this, we have attempted to develop robust wound dressing material with self-healing and antibacterial properties. We have cross-linked chitosan with 4-formyl phenylboronic acid (4-FPBA) and in situ generated dehydroascorbic acid (DHA) utilizing the dynamic imine and boronate ester linkages. Displaying a channeled microstructure in the SEM micrographs, the hydrogel exhibits a massive water uptake capacity of ∼900% at acidic pH. The hydrogel could completely self-heal within 3 min, and the results are further supported by rheological analysis. By virtue of positive surface charge, it shows a promising tissue adhesive property. Moreover, it affords clean and compliant removal from the wound surface via dissolution induced by dopamine to potentially reduce secondary scarring from peeling of wound dressings. The dressing could significantly act against skin infections caused by S. aureus bacteria with enhanced antimicrobial efficiency via loading of antibiotic drug, tetracycline hydrochloride. A sustained release of tetracycline and Curcumin was observed, which demonstrated the release ability for hydrophilic and hydrophobic bioactive agents. In-vitro studies revealed 93% cell viability with a hemolytic ratio as low as 2.5%, thereby presenting a good self-healing and biocompatible material for wound healing.

A ratiometric nanoplatform for fluorimetric and visual detection of Cu2+ and biothiols based on Eu MOFs and carbon dots

Herein, a ratiometric nanoplatform was established for fluorimetric and visual detection of Cu2+ and biothiols based on europium-based metal–organic frameworks (Eu MOFs) and carbon dots (CDs). Fluorescent Eu MOFs with red emission was facilely prepared via the coordination of Eu3+ with tetracycline (TC) and 2-[4-(2-hydroxyethyl)piperazin-1-yl] ethanesulfonic acid (Hepes). However, with addition of Cu2+, the fluorescence of Eu MOFs significantly decreased due to higher affinity of Cu2+ with TC, whereas the green fluorescence of CDs was not influenced by Cu2+, which served as an internal standard of the sensing platform. Interestingly, after introducing biothiols, the stronger coordination between Cu2+ and the sulfydryl of biothiols induced the release of TC to coordinate with Eu3+, thus recovering the fluorescence of Eu MOFs. The ratio changes of these two emissions accompanying by the distinct color variations of the solution under a 365 nm ultraviolet lamp could be used as output signals for fluorimetric and visual detection of Cu2+ and biothiols. The nanoplatform exhibited excellent sensing performance with limit detection as low as 0.57 μM for Cu2+, 0.54 μM for glutathione, 0.14 μM for homocyeteine and 0.42 µM for cysteine, respectively. In addition, it was successfully applied to detecting Cu2+ in environment water samples and biothiols in human serum samples, suggesting great potential for Cu2+ and biothiols determination in environmental and biological samples.

In Situ ATR-FTIR Studies on the β-Sheet Formation of Native and Regenerated Bombyx mori Silk Material in Solution and Its Potential for Drug Releasing Coatings.

Dynamic attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy at both solutions and coatings of a semicrystalline silk material derived from Bombyx mori was applied to monitor the β-sheet conformation, which is known to correlate with silk protein crystallinity. The secondary structure-sensitive Amide I band was analyzed. Two silk protein samples were studied: native-based silk buffer fibroin (NSF) was extracted from silk glands and regenerated silk fibroin (RSF) was extracted from degummed cocoons. Solutions of both NSF and RSF at 2 mg/mL featured low initial β-sheet contents of 5-12%, which further increased to 47-53% after 24 h. RSF and NSF solutions at 23 mg/mL also featured low initial β-sheet contents of 9-10%, which yet only slightly increased to 16-17% after 24 h. Coatings deposited from RSF solutions showed high surface integrity (Q > 99%) after rinsing in mineralized water, enabling interfacial drug delivery applications. RSF coatings were post-treated with either formic acid (FA) or pure methanol (MeOH) vapor to showcase inducibility of crystalline domains in RSF coatings. Such coatings were loaded with the model antibiotic drugs tetracycline (TCL) and streptomycin (STRP), and the sustained release of TCL was followed in contact with (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES) buffer. RSF/TCL coatings post-treated with formic acid (FA) vapor followed by methanol (MeOH) vapor showed a significantly lower (52%) initial burst of rather hydrophobic TCL compared to untreated RSF/TCL coatings (72%), while no such significant release difference was observed for hydrophilic STRP. This was rationalized by a specific interaction between nonpolar TCL and hydrophobic crystalline RSF domains.

Enhanced photocatalytic performance of NiFe2O4/ZnIn2S4 p-n heterojunction for efficient degradation of tetracycline

The persistent release of tetracycline into the environment significantly endangers both ecosystems and human health. Zinc indium sulfide (ZnIn2S4) capable to degrade tetracycline pollutants under visible light irradiation has attracted extensive attentions and great effort has been devoted to augment its catalytic efficacy. In this work, we synthesized a p-n heterojunction, NiFe2O4/ZnIn2S4, to enhance the carrier migration rate and explained the intrinsic mechanism by density functional theory. When the heterojunction was formed, carriers traversed from the n-type NiFe2O4 to the p-type ZnIn2S4, instigating the emergence of a built-in electric field to facilitate the separation of carriers. 2 %-NiFe2O4/ZnIn2S4 exhibited excellent photocatalytic efficiency in tetracycline (TC) degradation and total organic carbon (TOC) removal. Compared to pure ZnIn2S4 and NiFe2O4, the TC degradation rates of 2 %-NiFe2O4/ZnIn2S4 were 2.0 times and 16.9 times higher, respectively. Additionally, 2 %-NiFe2O4/ZnIn2S4 had a saturation magnetization intensity of 3.05 emu/g, allowing for rapid recovery of the catalyst under a magnetic field. Superoxide radicals (O2−) and holes (h+) were the primary active species driving the degradation process. Furthermore, potential reaction pathways of tetracycline in this photocatalytic process were determined and bioconcentration factor and developmental toxicity of the intermediate products were accessed. This work held great potentials for wastewater treatment and provided a pathway for the development of magnetic recyclable photocatalysts.

Functional network copolymeric hydrogels derived from moringa gum: Physiochemical, drug delivery and biomedical properties

The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These hydrogels are designed for use in drug delivery (DD) and wound hydrogels dressing (HYDR) applications. The copolymers were characterized by FESEM, EDX, AFM, FTIR, 13C NMR, XRD and DSC. Tetracycline release from hydrogel occurred gradually with a non-Fickian diffusion and was best described by the Hixson-Crowell kinetic model in artificial wound fluid. The HYDR demonstrated compatibility with blood, exhibited antioxidant properties and possessed tensile strength, in addition to their mucoadhesive characteristics. The copolymer dressings absorbed approximately 7 g of simulated fluid. The copolymers exhibited significant antioxidant activity, measuring at 84 % free radicals scavenging, during DPPH assay. These dressings demonstrated permeability to H2O and O2,. The hydrogel alone did not reveal antibacterial activities; however, when combined with antibiotic drug tetracycline, the dressings revealed notable antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The observed biomedical properties suggested that these hydrogels could serve as promising materials for drug delivery HYDR applications.

Chitosan-Type-A-Gelatin Hydrogels Used as Potential Platforms in Tissue Engineering for Drug Delivery.

Hydrogels are materials made of crosslinked 3D networks of hydrophilic polymer chains that can absorb and retain significant amounts of water due to their hydrophilic structure without being dissolved. In relation to alternative biomaterials, hydrogels offer increased biocompatibility and biodegradability, giving them distinct advantages. Thus, hydrogel platforms are considered to have the potential for the development of biomedical applications. In this study, the main objective was the development of hybrid hydrogels to act as a drug delivery platform. These hydrogels were made from chitosan (CH) and type A gelatin (G), two natural polymers that provide a supportive environment for cellular attachment, viability, and growth, thanks to their unique properties. Particularly, the use of gelatins for drug delivery systems provides biodegradability, biocompatibility, and non-toxicity, which are excellent properties to be used in the human body. However, gelatins have some limitations, such as thermal instability and poor mechanical properties. In order to improve those properties, the aim of this work was the development and characterization of hybrid hydrogels with different ratios of CH-G (100-0, 75-25, 50-50, 25-75, 0-100). Hydrogels were characterized through multiple techniques, including Fourier transform infrared (FTIR) spectroscopy, rheological and microstructural studies, among others. Moreover, a model hydrophilic drug molecule (tetracycline) was incorporated to evaluate the feasibility of this platform to sustain the release of hydrophilic drugs, by being tested in a solution of Phosphate Buffer Solution at a pH of 7.2 and at 37 °C. The results revealed that the synergy between chitosan and type A gelatin improved the mechanical properties as well as the thermal stability of it, revealing that the best ratios of the biopolymers are 50-50 CH-G and 75-25 CH-G. Thereby, these systems were evaluated in a controlled release of tetracycline, showing a controlled drug delivery of 6 h and highlighting their promising application as a platform for controlled drug release.

Polysilsesquioxane decorated ZIF-8 as a potential pH-responsive vehicle for topical delivery and release of acyclovir and tetracycline: Investigation of blood compatibility, cytotoxicity and antibacterial properties

In this research, poly-chloropropylmethyl-silsesquioxanen was prepared and decorated with ZIF-8 in order to investigate its loading capacity for acyclovir and tetracycline. Before and after drug loadings, the composites were characterized by FT-IR, SEM-EDS, XRD, and XPS analyses. Then, the in-vitro release of these drugs was investigated by UV–Vis spectroscopy in different buffers (pH = 5, 7.4, and 9.1). The results showed that the release of ACV reached a maximum amount of 41.3 mg at pH = 7.4 during 12 h. In comparison, the release of TC reached a maximum amount of 22.5 mg at pH = 5 during 6 h. The blood compatibility, in-vitro cytotoxicity on the L929 fibroblast cells line, and antibacterial assay against Staphylococcus aureus and Pseudomonas aeruginosa were also investigated for this composite as a drug carrier.

Synthesis of ZIF-8/PVA microspheres with the assistance of a microfluidic device and their controlled drug release properties

ZIF-8/PVA microspheres with an even size were synthesized with the assistance of a simple microfluidic device. The ZIF-8/PVA microdroplets were first generated in a simple co-flow microfluidic device using a PVA aqueous solution dispersed with ZIF-8 nanoparticles as the dispersed phase and fatty acid methyl ester (FAME) as the continuous phase. Subsequently, the ZIF-8/PVA microdroplets were further extracted to form ZIF-8/PVA microspheres. The influence of the type of continuous phase on the sphericity of microspheres was investigated and the effect of ZIF-8 content was studied. Further studies showed that decreasing the extraction rate and using additives of NaCl in the dispersed phase could improve the sphericity of the ZIF-8/PVA microspheres. Finally, the synthesized ZIF-8/PVA microspheres were used to study the loading and release of tetracycline. The results showed that the loading of ZIF-8/PVA microspheres was more than 5 times higher than that of pure PVA microspheres. The drug release time of ZIF-8/PVA microspheres was much longer than that of the PVA microspheres and the release rate was significantly affected by the pH of the environment.

Mucoadhesive Polymeric Polyologels Designed for the Treatment of Periodontal and Related Diseases of the Oral Cavity.

The study objective was to design and characterise herein unreported polyologels composed of a range of diol and triol solvents and polyvinyl methyl ether-co-maleic acid (PVM/MA) and, determine their potential suitability for the treatment of periodontal and related diseases in the oral cavity using suitable in vitro methodologies. Polyologel flow and viscoelastic properties were controlled by the choice of solvent and the concentration of polymer. At equivalent polymer concentrations, polyologels prepared with glycerol (a triol) exhibited the greatest elasticity and resistance to deformation. Within the diol solvents (PEG 400, pentane 1,5-diol, propane 1,2-diol, propane 1,3-diol, and ethylene glycol), PEG 400 polyologels possessed the greatest elasticity and resistance to deformation, suggesting the importance of distance of separation between the diol groups. Using Raman spectroscopy bond formation between the polymer carbonyl group and the diol hydroxyl groups was observed. Polyologel mucoadhesion was influenced by viscoelasticity; maximum mucoadhesion was shown by glycerol polyologels at the highest polymer concentration (20% w/w). Similarly, the choice of solvent and concentration of PVM/MA affected the release of tetracycline from the polyologels. The controlled release of tetracycline for at least 10 h was observed for several polyologels, which, in combination with their excellent mucoadhesion and flow properties, offer possibilities for the clinical use of these systems to treat diseases within the oral cavity.

Antioxidant cellulose nanofibers/lignin-based aerogels: a potential material for biomedical applications

BackgroundLignin is a naturally occurring and aromatic biopolymer with well-known antimicrobial and antioxidant properties. Thus, in this work, the use of cellulose nanofibers (CNF) and lignin to produce ultra-light aerogels for biomedical applications was studied. Aerogels containing varying amounts of lignin (0–30 wt%) and different concentrations of the crosslinking agent Fe3+ (25–100 mM) were developed.ResultsThe different bioaerogels were fully characterized and their physical, mechanical and bioactive properties analyzed. It was observed that the bioaerogels soluble fraction tends to decrease as the lignin content increases for the different Fe3+ concentrations, due to lignin–CNF interactions through hydrogen bonds. The bioaerogels containing lignin showed remarkable radical scavenging activity as the DPPH concentration decreased with time. This confirms the benefits of including lignin in bioaerogels to impart antioxidant properties. To study the suitability of the produced bioaerogels for controlled drug release, the release of tetracycline (TC) was studied. All of the bioaerogels released TC in a sustained manner for 6 h and presented similar profiles. However, the bioaerogels containing higher concentrations of crosslinker showed a higher release of TC. The TC loading conferred clear antimicrobial activity against S. aureus as expected, unlike the insignificant antimicrobial activity of the bioaerogels without TC. The biocompatibility of the samples was demonstrated for all materials produced (with and without TC loading) by the Kruskal–Wallis test with multiple comparisons. After observation of cell morphology, no significant differences were evident suggesting that the CNF–lignin bioaerogels present optimal biocompatibility for use in the biomedical and pharmaceutical industry.ConclusionsThe CNF–lignin bioaerogels presented in this work highlights their promising application as biomedical applications, such as wound dressings due to their biocompatibility, antimicrobial and antioxidant properties, as well as their swelling and solubility properties.Graphical

Ultrasound-assisted synthesis of MIL-88(Fe) conjugated starch-Fe3O4 nanocomposite: A safe antibacterial carrier for controlled release of tetracycline

A constructing antibiotic carrier with a sustained release profile is a promising method to stop long-term bacterial infection, which is of ideal interest in different biomedical fields. To end this, the present study aims to design a novel carrier based on the modification of biopolymeric starch for the rising possible interaction between carrier and antibiotic agent. We established an in-situ ultrasound-assisted method was applied to grow and create MIL-88(Fe) framework in the structure of magnetic polysaccharide (i.e., St/Fe3O4) synthesized by precipitation method resulting in St/Fe3O4/MIL-88(Fe) nanocomposite. It was loaded with a high amount of Tetracycline (TC) through its immersion into the TC aqueous solution. The release profile of TC-loaded St/Fe3O4/MIL-88(Fe) displays a lower initial burst release (about 26 % after 12 h) and followed by a controlled and sustained release (about 73 % up to 168 h) in the simulated physiological environment at pH 7.4. The in vitro cytotoxicity showed good cytocompatibility against Human skin fibroblast (HFF-1) cells. TC-loaded St/Fe3O4/MIL-88(Fe) showed higher antibacterial activity against both S. aureus and E. coli with the MIC value of 64 and 128 μg·mL−1, respectively.

Semi-Interpenetrating Polymer Networks Based on Hydroxy-Ethyl Methacrylate and Poly(4-vinylpyridine)/Polybetaines, as Supports for Sorption and Release of Tetracycline.

Semi-interpenetrating polymer networks (semi-IPN) represent a type of polymeric material that has gained increasing amount of interest for their potential biomedical application. This study presents the synthesis, characterization and tetracycline loading/release capacities of semi-IPNs based on hydroxyethyl methacrylate (HEMA) and poly(4-vinylpyridine) (P4VP) or poly (1-vinyl-4-(1-carboxymethyl) pyridinium betaine) (P4VPB-1) and poly (1-vinyl-4-(2-carboxyethyl) pyridinium betaine) (P4VPB-2). The optimization of the semi-IPNs synthesis was achieved by studying the influence of reaction parameters (chemical structure of the cross-linking agent, HEMA:crosslinker ratio, HEMA:linear polymers ratio and the type of solvent of the linear polymers) on the yield of obtaining semi-IPNs and swelling capacity of these systems. Fourier-transform infrared analysis and scanning electron microscopy highlighted the chemical structures and morphologies of the semi-IPNs. The higher swelling capacity was observed in the case of the PHEMA/P4VPB-2 network due to the increased hydrophilicity of P4VPB-2 compared with P4VP and P4VPB-1 polymers. In vitro release studies of tetracycline reveal that the release mechanism is represented by non-Fickian diffusion being controlled by both diffusion and swelling processes. The antimicrobial activity of semi-IPN-tetracycline systems was tested against E. coli and S. aureus, demonstrating that tetracycline is released from the semi-IPN and retains its bactericidal activity. An increased value of the inhibition zone diameter compared with that of tetracycline indicates the possibility that the semi-IPN containing P4VPB-2 also exhibits intrinsic antimicrobial activity due to the presence of the polybetaine in the network structure.

Bacterial Cellulose–Polyvinyl Alcohol Based Complex Composites for Controlled Drug Release

Drug-loaded mono- and multilayer composite membranes were prepared. The composites, based on nano-fibrillated bacterial cellulose, nano-powdered bacterial cellulose, and polyvinyl alcohol, all biocompatible and biodegradable, were characterized in terms of basic factors related to drug diffusivity and mass transfer: swelling ability, water solubility, and water vapor permeability. Tetracycline hydrochloride was used in this case as drug model. Drug release was evaluated in an aqueous environment for two concentration levels of the antibiotic, and mathematical modeling was applied to fit experimental data. Tetracycline release was influenced by a membranes’ structure, layers’ composition, and by a membranes’ thickness. Bacterial cellulose nanofibrils proved to be the key factor in achieving suitable drug release profiles. Thus, sustained antibiotic delivery was obtained for several days in the case of multilayer composites. The composites proved drug stability and antibacterial efficiency before and after TC-HCl continuous release for several days.

Strontium-doped apatitic bone cements with tunable antibacterial and antibiofilm ability.

Injectable calcium phosphate cements (CPCs) represent promising candidates for the regeneration of complex-shape bone defects, thanks to self-hardening ability, bioactive composition and nanostructure offering high specific surface area for cell attachment and conduction. Such features make CPCs also interesting for functionalization with various biomolecules, towards the generation of multifunctional devices with enhanced therapeutic ability. In particular, strontium-doped CPCs have been studied in the last years due to the intrinsic antiosteoporotic character of strontium. In this work, a SrCPC previously reported as osteointegrative and capable to modulate the fate of bone cells was enriched with hydroxyapatite nanoparticles (HA-NPs) functionalized with tetracycline (TC) to provide antibacterial activity. We found that HA-NPs functionalized with TC (NP-TC) can act as modulator of the drug release profile when embedded in SrCPCs, thus providing a sustained and tunable TC release. In vitro microbiological tests on Escherichia coli and Staphylococcus aureus strains proved effective bacteriostatic and bactericidal properties, especially for the NP-TC loaded SrCPC formulations. Overall, our results indicate that the addition of NP-TC on CPC acted as effective modulator towards a tunable drug release control in the treatment of bone infections or cancers.

Antibacterial effect and tetracycline release of poly(Ɛ-caprolactone) matrices obtained by iodine polymerization

The development of devices to controlled the release of drugs are in constant technological innovation. The aim is to improve the release of drugs on target areas. Poly (ε-caprolactone) (PCL) has been widely investigated because of degradation rate, biocompatibility, availability, no toxicity, cost and good adhesion to a large number of drugs. Thus, in the present study was associated polymer PCL with antibiotics tetracycline as local delivery system. PCL was obtained by ring-opening polymerization of monomer Ɛ-caprolactone (Ɛ-CL). The samples were characterized by fourier transformed infrared (FTIR), differential scanning calorimetric (DSC), thermogravimetric analyses (TGA) and X-ray diffraction analysis (X-rays). Likewise, was investigated antimicrobial activity against gram-positive bacteria (S. aureus) and gram-negative bacteria (E. coli, P. mirabilis, P. aeruginosa and K. pneumoniae). According to the results, the antibiotics tetracycline has been successfully incorporated to PCL matrices. They release tetracycline in the ideal rates and shows antibacterial activity. So, this material has a potential to been used in implants for drug release.

Hybrid system with stable structure of hard/soft tissue substitutes induces re-osseointegration in a rat model of biofilm-mediated peri-implantitis.

Re-osseointegration of an infected/contaminated dental implant poses major clinical challenges. We tested the hypothesis that the application of an antibiotic-releasing construct, combined with hard/soft tissue replacement, increases the efficacy of reconstructive therapy. We initially fabricated semi-flexible hybrid constructs of β-TCP/PHBHHx, with tetracycline (TC) (TC amounts: 5%, 10%, and 15%). Thereafter, using in vitro assays, TC release profile, attachment to rat bone marrow-derived stem cells (rBMSCs) and their viability as well as anti-bacterial activity were determined. Thereafter, regenerative efficacies of the three hybrid constructs were assessed in a rat model of peri-implantitis induced by Aggregatibacter actinomycetemcomitans biofilm; control animals received β-TCP/Bio-Gide and TC injection. Eight weeks later, maxillae were obtained for radiological, histological, and histomorphometric analyses of peri-implant tissues. Sulcus bleeding index was chronologically recorded. Serum cytokines levels of IL-6 and IL-1β were also evaluated by enzyme-linked immunosorbent assay. Substantial amounts of tetracycline, from hybrid constructs, were released for 2 weeks. The medium containing the released tetracycline did not affect the adhesion or viability of rBMSCs; however, it inhibited the proliferation of A. actinomycetemcomitans. Osteogenesis and osseointegration were more marked for the 15% hybrid construct group than the other two groups. The height of attachment and infiltration of inflammatory cells within fibrous tissue was significantly reduced in the experimental groups than the control group. Our protocol resulted in re-osseointegration on a biofilm-contaminated implant. Thus, an antibiotic releasing inorganic/organic construct may offer a therapeutic option to suppress infection and promote guided tissue regeneration thereby serving as an integrated multi-layer substitute for both hard/soft tissues.

Application of a nanocomposite based on modified salep glucomannan for monitoring controlled release of tetracycline as a model drug

Application of a nanocomposite based on modified salep glucomannan for monitoring controlled release of tetracycline as a model drug

Wound healing and antibacterial chitosan-genipin hydrogels with controlled drug delivery for synergistic anti-inflammatory activity

Chitosan (CHI) based hydrogels promote wound healing and relieve inflammations and chronic infections. However, in hardly healable ulcers with excessively painful inflammations, anti-inflammatory activity of hydrogels can be enhanced by the sustained release of non-steroidal anti-inflammatory drugs or combining them with antibiotics. Thus, CHI was crosslinked with genipin (GP) to obtain biocompatible hydrogels. Moreover, their antibacterial activity was confirmed against Staphylococcus aureus and Escherichia coli with an almost 100% bacteria reduction and a potential antibacterial efficacy (R > 2). Furthermore, hydrogels effective healing of ulcerated wounds was corroborated by a significant improvement in metabolic activity (95.58 ± 4.40%), collagen and elastin quantities (1.48 ± 0.07 μg collagen and 5.82 ± 0.73 μg elastin per mg dermal tissue) and histological analysis. Finally, the sustained release of acetylsalicylic acid (ASA), cefuroxime (CFX), tetracycline (TCN) and amoxicillin (AMX) were studied, as well as their anti-inflammatory activity. Results confirm the synergistic anti-inflammatory activity by the significant reduction in the amount of pro-inflammatory cytokines when ASA was combined with CFX (5.39 ± 0.81 ng·mL−1 TNF-α), TCN (4.70 ± 0.21 ng·mL−1 TNF-α and 49.06 ± 9.64 ng·mL−1 IL-8), and AMX (2.28 ± 0.36 ng·mL−1 TNF-α, 14.84 ± 5.57 ng·mL−1 IL-8, and total IL-6 removal).

Near-Infrared Light-Controllable Multifunction Mesoporous Polydopamine Nanocomposites for Promoting Infected Wound Healing.

The successful treatment of infected wounds requires strategies with effective antimicrobial, anti-inflammatory, and healing-promoting properties. Accordingly, the use of Cu2+ and tetracycline (TC), which can promote angiogenesis, re-epithelialization, and collagen deposition, also antibacterial activity, at the wound site, has shown application prospects in promoting infected wound repair. However, realizing controllable release to prolong action time and avoid potential toxicities is critical. Moreover, near-infrared light (NIR)-activated mesoporous polydopamine nanoparticles (MPDA NPs) reportedly exert anti-inflammatory effects by eliminating the reactive oxygen species generated during inflammatory responses. In this study, we assess whether Cu2+ and TC loaded in MPDA NPs can accelerate infected wound healing in mice. In particular, Cu2+ is chelated and immobilized on the surface of MPDA NPs, while a thermosensitive phase-change material (PCM; melting point: 39-40 °C), combined with antibiotics, was loaded into the MPDA NPs as a gatekeeper (PPMD@Cu/TC). Results show that PPMD@Cu/TC exhibits significant great photothermal properties with NIR irradiation, which induces the release of Cu2+, while inducing PCM melting and, subsequent, TC release. In combination with anti-inflammatory therapy, NIR-triggered Cu2+ and TC release enables the nanocomposite to eradicate bacterial wound infections and accelerate healing. Importantly, negligible damage to primary organs and satisfactory biocompatibility were observed in the murine model. Collectively, these findings highlight the therapeutic potential of this MPDA-based platform for controlling bacterial infection and accelerating wound healing.