Hyaluronic acid-coated ZIF-8 for the treatment of pneumonia caused by methicillin-resistant Staphylococcus aureus

Chemoproteomics unveils Sofalcone targeting ribosomal proteins to inhibit protein synthesis in Staphylococcus aureus

The escalating threat of antibiotic resistance, particularly in Staphylococcus aureus (including methicillin-resistant strains, MRSA), underscores the urgent need for novel therapeutics. Sofalcone (Sof), a chalcone derivative from Sophora subprostrata with established anti-inflammatory and anti-ulcer properties, exhibits promising yet underexplored antibacterial activity. Here, we demonstrate that Sof potently inhibits S. aureus and MRSA while showing minimal cytotoxicity in human cells. Notably, Sof synergized with amoxicillin, and significantly reduced the pathogenicity of S. aureus through inhibiting biofilm formation addressing key virulence factors. Through chemoproteomic profiling using a clickable Sof-derived probe, ribosomal proteins, specifically the 50S subunit protein rplB, were identified as primary targets. Sof covalently binds to rplB via cysteine residues, as validated by cellular thermal shift assays, microscale thermophoresis, and competition assays. Bio-orthogonal noncanonical amino acid tagging revealed that Sof disrupts bacterial protein synthesis by impairing ribosomal function, a mechanism distinct from conventional antibiotics. In a murine model of S. aureus-induced acute lung injury, Sof greatly reduced bacterial load in lungs, attenuated systemic inflammation, and mitigated histopathological damage. Its dual antibacterial and anti-inflammatory efficacy, coupled with activity against Gram-negative Escherichia coli, highlights broad-spectrum potential. This study unveils a covalent ribosomal-targeting strategy, positioning Sof as a multifaceted candidate against multidrug-resistant infections. Our findings bridge natural product pharmacology and mechanistic antimicrobial discovery, offering a template for combating the global antibiotic resistance crisis.

Development of ROS-responsive collagen-based hemostatic sponges for the repair of MRSA-infected wounds

Uncontrolled bleeding and infections, particularly from drug-resistant bacteria like Methicillin-Resistant Staphylococcus aureus (MRSA), pose significant challenges in clinical wound management, delaying healing, increasing patient discomfort, and elevating healthcare costs. This study introduces a novel reactive oxygen species (ROS)-responsive collagen-based hemostatic sponge designed to enhance wound healing and minimize blood loss, especially in MRSA-infected wounds. By chemically modifying the carboxyl groups of collagen with amino-rich oligomers, the primary amino content was increased, enhancing drug loading capacity-particularly for vancomycin-while also improving the sponge's mechanical properties, hemostatic performance, and biological stability. The ROS-responsive covalent bonding of vancomycin facilitated controlled vancomycin release in response to ROS, offering superior antibacterial efficacy and specifically targeting MRSA more effectively than conventional non-ROS-responsive approaches. In MRSA-infected full-thickness skin repair models, the ROS-responsive vancomycin-loaded sponge significantly enhanced wound healing and skin regeneration compared to both the physical adsorption group and the non-ROS-responsive release group. These results underscore the potential of the ROS-responsive collagen composite as an advanced hemostatic material with enhanced antibacterial capabilities, providing rapid hemostasis and improved healing outcomes for complex or infected wounds.

Zeolite Imidazole Framework-8 Exacerbates Astrocyte Activation and Oxidative Stress in the Brain of Rats

Metal-organic frameworks (MOFs) have been gaining significant attention due to their potential application in medicine. Here, we investigated the effect of zeolite imidazole framework-8 (ZIF-8) on neuro-behavioral parameters, histopathology, inflammation, and oxidative stress levels of rats' brain samples. Forty-eight male Wistar rats were injected by four injections of saline or ZIF-8 at different doses of 5, 10, or 20 mg/kg via the caudal vein. Y-Maze, Morris-Water Maze (MWM), and three chamber tests were conducted to explore working memory, spatial learning and memory, and social interactions, respectively. Histological staining and immunohistochemistry were used to evaluate pathological changes and astrocyte activation levels. The inflammation levels were measured using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). The total antioxidant capacity (TAC) and oxidative stress production were assessed by biochemical assays. The results showed that ZIF-8 induces neuromotor impairment dose-dependently. Although histopathological studies indicated increased neuronal loss, inflammatory changes, and elevated active astrocytes in the hippocampus, the expression levels of IL-1β and TNF-α were not significantly increased in ZIF-8-treated rats. The TAC level significantly reduced and the malondialdehyde (MDA) level remarkably increased in the brain tissues. Our findings suggest that administration of ZIF-8 induce neuromotor impairment, probably through amplified inflammation and oxidative stress.

pH-responsive ZIF-8 nanoplatform co-loaded with DSF and ICG for multiple synergistic antitumor therapy

Disulfiram (Allensworth et al.), an "old drug" for the treatment of chronic alcohol dependence, has received extensive attention due to its potential antitumor activity for new medical applications. However, the application of DSF in cancer therapy was limited by its extremely terrible solubility in water. Meanwhile, Cu2+ was used to enhance the antitumor activity of DSF in most of the current studies, while few studies related to the combination of Zn2+ and DSF. Herein, we developed a pH-responsive hyaluronic acid/polyethylene glycol-graft-polyglutamic acid (HPG) modified zeolitic imidazolate framework-8 (ZIF-8) nanoparticle system (ID@ZIF-8@HPG) to achieve the co-delivery of Zn2+/indocyanine green (ICG)/DSF and the improvement of the solubility of DSF, which conducted an efficient anticancer effectiveness through its chemotherapy/photothermal/photodynamic multiple synergistic antitumor effects. The obtained ID@ZIF-8@HPG demonstrated acid-sensitive and photothermal-sensitive release behavior, which contributed to the release of DSF from nanoparticles within tumor cells upon laser irradiation of the tumor site and was beneficial to reduce the toxicity produced by chemotherapy. In vitro experiments demonstrated that ID@ZIF-8@HPG could be better taken up by tumor cells, resulting in excellent photothermal and photodynamic properties. In addition, ID@ZIF-8@HPG exhibited outstanding intratumor retention capacity and powerful tumor cell-killing ability while maintaining favorable biocompatibility. In summary, this study presents a promising nanoparticle delivery platform for cancer treatment, broadening the application of ZIF-8 in the field of tumor combination therapy.

One stone, three birds: Construction of Cu/ZIF-8@DSF@GOx/HA nanoplatform for synergistic starvation therapy enhanced chemo-/chemodynamic therapy

Disulfiram (DSF), as a sixpenny drug for the treatment of alcohol dependence, has demonstrated copper-dependent chemotherapy (CT) effects in recent years. However, as the most common modality in clinical treatment, prolonged use of CT will lead to multidrug resistance (MDR). In this work, a versatile and ingenious nanoparticle Cu/ZIF-8@DSF@GOx/HA (CZDGH) was constructed to deliver DSF, Cu2+ and GOx to tumor cells. Once internalized by tumor cells, GOx depletes glucose blocking the energy supply leading to ST. Then DSF chelates with Cu2+ in situ to generate CuETs, achieving toxicity-intensified CT, the reduced ATP in this process also inhibits the efflux function of P-gp. In the meantime, Cu2+ consumes glutathione (GSH) to enhance oxidative stress, and the converted Cu+ catalyzes internal and external sources of H2O2 into •OH, heightening chemodynamic therapy (CDT). The experimental results demonstrate remarkable multimodal synergistic anticancer effects that overcome MDR.

Cytotoxic effects of bee venom-loaded ZIF-8 nanoparticles on thyroid cancer cells: a promising strategy for targeted therapy

Thyroid cancer continues to be a notable health issue, requiring the creation of novel treatment methods to enhance patient results. The objective of this study is to investigate the potential of utilizing bee venom (BV)-loaded zeolitic imidazolate framework-8 (ZIF-8) nanoparticles as a novel strategy for specifically targeting and treating medullary thyroid cancer cells. Due to their wide surface area and configurable pore size, ZIF-8 nanoparticles are ideal for drug delivery. Bee venom's cytotoxic capabilities are used in ZIF-8 nanoparticles to target thyroid cancer cells more effectively. ZIF-8 nanoparticles containing bee venom were tested on TT medullary thyroid cancer cell lines. The effects of these nanoparticles on cell viability, proliferation, and apoptosis were investigated. IC50 value at 24 h for BV-ZIF-8 nanoparticles in TT medullary thyroid carcinoma cells was determined to be 17.19 µg/mL, while the IC50 value at 48 h was determined to be 16.39 µg/mL. It has been demonstrated that nanoparticle treatment upregulates the Bax and caspase-3 genes while downregulating the Bcl-2, CCND1, and CDK4 genes. Additionally, it was observed that oxidative stress was triggered in the nanoparticle-treated group. Furthermore, an examination of its mechanisms was conducted, with a specific emphasis on the modulation of critical signaling pathways that are implicated in the progression of cancer. In thyroid cancer cells, ZIF-8 nanoparticles infused with bee venom promote programmed cell death and impair key biological processes.

Bovine serum albumin-coated ZIF-8 nanoparticles to enhance antitumor and antimetastatic activity of methotrexate: in vitro and in vivo study

In this study, a bovine serum albumin-decorated zeolitic imidazolate framework (ZIF-8@BSA) was used to enhance the anticancer and antimetastatic properties of methotrexate. SEM, DLS, FT-IR, and XRD confirmed the physicochemical suitability of the developed nanoparticles. According to the SEM analysis, the mean size of ZIF-8 nanoparticles was 68.5 ± 13.31 nm. The loading capacity and encapsulation efficiency of MTX@ZIF-8@BSA were 28.77 ± 2.54% and 96.3 ± 0.67%, respectively. According to the in vitro hemolysis test, MTX@ZIF-8@BSA showed excellent blood compatibility. MTX@ZIF-8@BSA exhibited pH sensitivity, releasing more MTX at pH 5.4 (1.73 times) than at pH 7.4. The IC50 value of MTX@ZIF-8@BSA on 4T1 cells was 32.7 ± 7.3 µg/mL after 48 h of treatment, outperforming compared to free MTX with an IC50 value of 53.3 ± 3.7 µg/mL. Treatment with MTX@ZIF-8@BSA resulted in superior tumor growth suppression in tumor-bearing mice than free MTX. Furthermore, based on histopathology tests, MTX@ZIF-8@BSA reduced the metastasis in lung and liver tissues. While there was not any noticeable toxicity in the vital organs of MTX@ZIF-8@BSA-receiving mice, free methotrexate resulted in severe toxicity in the kidneys and liver. According to the preliminary in vitro and in vivo findings, MTX@ZIF-8@BSA presents an attractive drug delivery system candidate for breast cancer due to its enhanced antitumor efficacy and lower toxicity.

Hyaluronic Acid Receptor-Mediated Nanomedicines and Targeted Therapy

Hyaluronic acid (HA) is a naturally occurring polysaccharide found in the extracellular matrix with broad applications in disease treatment. HA possesses good biocompatibility, biodegradability, and the ability to interact with various cell surface receptors. Its wide range of molecular weights and modifiable chemical groups make it an effective drug carrier for drug delivery. Additionally, the overexpression of specific receptors for HA on cell surfaces in many disease states enhances the accumulation of drugs at pathological sites through receptor binding. In this review, the modification of HA with drugs, major receptor proteins, and the latest advances in receptor-targeted nano drug delivery systems (DDS) for the treatment of tumors and inflammatory diseases are summarized. Furthermore, the functions of HA with varying molecular weights of HA in vivo and the selection of drug delivery methods for different diseases are discussed.

Concanavalin-conjugated zinc-metal-organic framework drug for pH-controlled and targeted therapy of wound bacterial infection

Wounds are prone to infection which may be fatal to the life of the patient. The use of antibiotics is essential for managing bacterial infections in wounds, but the long-term use of high doses of antibiotics may lead to bacterial drug resistance and even to creation of superbacteria. Therefore, the development of targeted antimicrobial treatment strategies and the reduction in antibiotic usage are of utmost urgency. In this study, a multifunctional nanodrug delivery system (Cef-rhEGF@ZIF-8@ConA) for the treatment of bacteriostatic infection was synthesized through self-assembly of Zn2+, cefradine (Cef) and recombinant human epidermal growth factor (rhEGF), then conjugated with concanavalin (ConA), which undergoes pH-responsive degradation to release the drugs. First, ConA can specifically combine with bacteria and inhibit the rapid release of Zn2+ ions, thus achieving a long-acting antibacterial effect. Cef exerts its antibacterial effect by inhibiting the synthesis of bacterial membrane proteins. Finally, Zn2+ ions released from the Zn-metal-organic framework (MOF) demonstrate bacteriostatic properties by enhancing the permeability of the bacterial cell membrane. Furthermore, rhEGF upregulates angiogenesis-associated genes, thereby promoting angiogenesis, re-epithelialization and wound healing processes. The results showed that Cef-rhEGF@ZIF-8@ConA has good biocompatibility, with antibacterial efficacy against Staphylococcus aureus and Escherichia coli of 99.61 % and 99.75 %, respectively. These nanomaterials can inhibit the release of inflammatory cytokines and promote the release of anti-inflammatory cytokines, while also stimulating the proliferation of fibroblasts to facilitate wound healing. Taken together, the Cef-rhEGF@ZIF-8@ConA nanosystem is an excellent candidate in clinical therapeutics for bacteriostatic infection and wound healing.

Enhanced anti-tumor and anti-metastatic activity of quercetin using pH-sensitive Alginate@ZIF-8 nanocomposites:in vitroandin vivostudy

Quercetin (Qc) possesses anti-cancer properties, such as cell signaling, growth suppression, pro-apoptotic, anti-proliferative, and antioxidant effects. In this study, we developed an alginate-modified ZIF-8 (Alg@ZIF-8) to enhance the anti-tumor efficacy of Qc. The developed alginate-modified quercetin-loaded ZIF-8 (Alg@Qc@ZIF-8) was characterized using scanning electron microscope (SEM), dynamic light scattering (DLS), fourier transform infrared spectroscopy Thermogravimetric analysis, Brunauer-Emmett-Teller, and x-ray diffraction. The drug release pattern was evaluated at pH 5.4 and 7.4. The cytotoxicity of nanoparticles was assessed on the 4T1 cell line. Finally, the anti-tumor activity of Alg@Qc@ZIF-8 was evaluated in 4T1 tumor-bearing mice. SEM showed that the nanoparticles were spherical with a diameter of mainly below 50 nm. The DLS showed that the developed nanoparticles' hydrodynamic diameter, zeta potential, and polydispersity index were 154.9 ± 7.25 nm, -23.8 ± 5.33 mV, and 0.381 ± 0.09, respectively. The drug loading capacity was 10.40 ± 0.02%. Alg@Qc@ZIF-8 exhibited pH sensitivity, releasing more Qc at pH 5.4 (about 3.62 times) than at pH 7.4 after 24 h. Furthermore, the IC50value of Alg@Qc@ZIF-8 on the 4T1 cell line was 2.16 times lower than net Qc. Importantly, in tumor-bearing mice, Alg@Qc@ZIF-8 demonstrated enhanced inhibitory effects on tumor growth and lung metastasis compared to net Qc. Considering thein vitroandin vivooutcomes, Alg@Qc@ZIF-8 might hold great potential for effective breast cancer management.

Current status of controlled onco-therapies based on metal organic frameworks

Despite consecutive efforts devoted to the establishment of innovative therapeutics for cancer control, cancer remains as a primary global public health concern. Achieving controlled release of anti-cancer agents may add great value to the field of oncology that requires the involvement of nanotechnologies. Metal organic frameworks (MOFs) hold great promise in this regard owing to their unique structural properties. MOFs can act as superior candidates for drug delivery given their porous structure and large loading area, and can be prepared into anti-cancer therapeutics by incorporating stimuli-sensitive components into the ligands or nodes of the framework. By combing through chemical and physical features of MOFs favorable for onco-therapeutic applications and current cancer treatment portfolios taking advantages of these characteristics, this review classified MOFs feasible for establishing controlled anti-cancer modalities into 6 categories, outlined the corresponding strategies currently available for each type of MOF, and identified understudied areas and future opportunities towards innovative MOF design for improved or expanded clinical anti-cancer applications.

Novel pH-responsive alginate-stabilized curcumin-selenium-ZIF-8 nanocomposites for synergistic breast cancer therapy

In this study, a novel selenium@zeolitic imidazolate framework core/shell nanocomposite stabilised with alginate was used to improve the anti-tumour activity of curcumin. The developed alginate-stabilised curcumin-loaded selenium@zeolitic imidazolate framework (Alg@Cur@Se@ZIF-8) had a mean diameter of 159.6 nm and polydispersity index < 0.25. The release of curcumin from the nanocarrier at pH 5.4 was 2.69 folds as high as at pH 7.4. The bare nanoparticles showed haemolytic activity of about 12.16% at a concentration of 500 µg/mL while covering their surface with alginate reduced this value to 5.2%. By investigating cell viability, it was found that Alg@Cur@Se@ZIF-8 caused more cell death than pure curcumin. Additionally, in vivo studies showed that Alg@Cur@Se@ZIF-8 dramatically reduced tumour growth compared to free curcumin in 4T1 tumour-bearing mice. More importantly, the histological study confirmed that the developed drug delivery system successfully inhibited lung and liver metastasis while causing negligible toxicity in vital organs. Overall, due to the excellent inhibitory activity on cancerous cell lines and tumour-bearing animals, Alg@Cur@Se@ZIF-8 can be considered promising for breast cancer therapy.

Preparation and biological evaluation of antibody targeted metal-organic framework drug delivery system (TDDS) in Her2 receptor-positive cells

In this study, we designed and prepared a trastuzumab-coupled drug delivery system with pH response characteristics using mesoporous zeolitic imidazolate framework-8 (ZIF-8) as the carrier, Trastuzumab@ZIF-8@DOX. As results, the targeted drug delivery system (TDDS) ultimately showed high drug loading and good biocompatibility. The cumulative curve of drug release indicated that the early leakage levels were low under neutral pH conditions. However, under acidic pH conditions, there was an effective enhancement in drug release, indicating the presence of an explicit pH-triggered drug release mechanism. The results indicate that the prepared nanoparticles have the potential to serve as drug delivery systems, as they can release the loaded drug in a controlled manner. The results of cellular uptake tests showed that the uptake of the nanoparticles was greatly enhanced by the internalization mediated by the HER2 antibody. This finding indicates that the prepared nanoparticles can selectively target cancer cells that overexpress HER2. When the doxorubicin dose was 5 μg/ml, the survival rate of SK-BR-3 cells (cancer cells) was 47.75 %, and the survival rate of HaCaT cells (healthy cells) was 75.25 % when co-cultured with both cells. The therapeutic efficacy of Trastuzumab@ZIF-8@DOX was assessed on BALB/c nude mice to validate its potential as an effective drug delivery system for tumor inhibition in vivo. In conclusion, these findings demonstrate the specificity-targeted and pH-responsive nature of this smart drug delivery system, highlighting its promising prospects for efficient and controllable cancer treatment applications.

Synthesis of structure-defined β-1,4-GlcNAc-modified wall teichoic acids as potential vaccine against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a high priority pathogen due to its life-threating infections to human health. Development of prophylactic or therapeutic anti-MRSA vaccine is a potential approach to treat S. aureus infections and overcome the resistance crisis. β-1,4-GlcNAc glycosylated wall teichoic acids (WTAs) derived from S. aureus are a new type of antigen that is closely associated with β-lactam resistance. In this study, structure-defined β-1,4-GlcNAc-modified WTAs varied in chain length and numbers of GlcNAc modification were synthesized by an ionic liquid-supported oligosaccharide synthesis (ILSOS) strategy in high efficiency and chromatography-free approach. Then the obtained WTAs were conjugated with tetanus toxin (TT) as vaccine candidates and were further evaluated in a mouse model to determine the structure-immunogenicity relationship. In vivo immunological studies revealed that the WTAs-TT conjugates provoked robust T cell-dependent responses and elicited high levels of specific anti-WTAs IgG antibodies production associated with the WTAs structure including chain length as well as the β-1,4-GlcNAc modification pattern. Heptamer WTAs conjugate T6, carrying three copy of β-1,4-GlcNAc modified RboP, was identified to elicit the highest titers of specific antibody production. The T6 antisera exhibited the highest recognition and binding affinity and the most potent OP-killing activities to MSSA and MRSA cells. This study demonstrated that β-1,4-GlcNAc glycosylated WTAs are promising antigens for further development against MRSA.

Advances in surface-modified nanometal-organic frameworks for drug delivery

Nanometal-organic frameworks (NMOFs) are porous network structures composed of metal ions or metal clusters through self-assembly. NMOFs have been considered as a promising nano-drug delivery system due to their unique properties such as pore and flexible structures, large specific surface areas, surface modifiability, non-toxic and degradable properties. However, NMOFs face a series complex environment during in vivo delivery. Therefore, surface functionalization of NMOFs is vital to ensure that the structure of NMOFs remain stable during delivery, and can overcome physiological barriers to deliver drugs more accurately to specific sites, and achieve controllable release. In this review, the first part summarizes the physiological barriers that NMOFs faced during drug delivery after intravenous injection and oral administration. The second part summarizes the current main ways to load drugs into NMOFs, mainly including pore adsorption, surface attachment, formation of covalent/coordination bonds between drug molecules and NMOFs, and in situ encapsulation. The third part is the main review part of this paper, which summarizes the surface modification methods of NMOFs used in recent years to overcome the physiological barriers and achieve effective drug delivery and disease therapy, which are mainly divided into physical modifications and chemical modifications. Finally, the full text is summarized and prospected, with the hope to provide ideas for the future development of NMOFs as drug delivery.

Recent advances in targeted antibacterial therapy basing on nanomaterials

Bacterial infection has become one of the leading causes of death worldwide, particularly in low-income countries. Despite the fact that antibiotics have provided successful management in bacterial infections, the long-term overconsumption and abuse of antibiotics has contributed to the emergence of multidrug resistant bacteria. To address this challenge, nanomaterials with intrinsic antibacterial properties or that serve as drug carriers have been substantially developed as an alternative to fight against bacterial infection. Systematically and deeply understanding the antibacterial mechanisms of nanomaterials is extremely important for designing new therapeutics. Recently, nanomaterials-mediated targeted bacteria depletion in either a passive or active manner is one of the most promising approaches for antibacterial treatment by increasing local concentration around bacterial cells to enhance inhibitory activity and reduce side effects. Passive targeting approach is widely explored by searching nanomaterial-based alternatives to antibiotics, while active targeting strategy relies on biomimetic or biomolecular surface feature that can selectively recognize targeted bacteria. In this review article, we summarize the recent developments in the field of targeted antibacterial therapy based on nanomaterials, which will promote more innovative thinking focusing on the treatment of multidrug-resistant bacteria.

Debridement of contaminated implants using air-polishing coupled with pH-responsive maximin H5-embedded metal-organic frameworks

The primary goal of peri-implantitis treatments remains the decontamination of implant surfaces exposed to polymicrobial biofilms and renders biocompatibility. In this study, we reported a synergistic strategy for the debridement and re-osteogenesis of contaminated titanium by using erythritol air abrasion (AA) coupled with an as-synthesized pH-responsive antimicrobial agent. Here, the anionic antibacterial peptide Maximin H5 C-terminally deaminated isoform (MH5C) was introduced into the Zeolitic Imidazolate Frameworks (ZIF-8) via a one-pot synthesis process. The formed MH5C@ZIF-8 nanoparticles (NPs) not only possessed suitable stability, but also guarantee the slow-release effect of MH5C. Antibacterial experiments revealed that MH5C@ZIF-8 NPs exhibited excellent antimicrobial abilities toward pathogenic bacteria of peri-implantitis, confirming ZIF-8 NPs as efficient nanoplatforms for delivering antibacterial peptide. To evaluate the comprehensive debridement efficiency, single-species as well as mixed-species biofilms were successively established on commercially used titanium surfaces and decontaminated with different methods: removed only by erythritol air abrasion, treated merely with MH5C@ZIF-8 NPs, or received both managements. The results demonstrated that only erythritol air abrasion accompanied with MH5C@ZIF-8 NPs at high concentrations eliminated almost all retained bacteria and impeded biofilm rehabilitation, while neither erythritol air abrasion nor MH5C@ZIF-8 NPs alone could achieve this. Subsequently, we evaluated the re-osteogenesis on previously contaminated surfaces which were treated with different debridement methods afterwards. We found that cell growth and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) in the group received both treatments (AA + MH5C@ZIF-8) were higher than those in other groups. Our work emphasized the great potential of the synergistic therapy as a credible alternative for removing microorganisms and rendering re-osseointegration on contaminated implant surfaces, boding well for the comprehensive applications in peri-implantitis treatments.

Nanomaterials for Delivering Antibiotics in the Therapy of Pneumonia

Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia.

Effect of MA01 rhamnolipid on cell viability and expression of quorum-sensing (QS) genes involved in biofilm formation by methicillin-resistant Staphylococcus aureus

A group of biosurfactants, called rhamnolipids, have been shown to have antibacterial and antibiofilm activity against multidrug-resistant bacteria. Here, we examined the effect of rhamnolipid biosurfactants extracted from Pseudomonas aeruginosa MA01 on cell growth/viability, biofilm formation, and membrane permeability of methicillin-resistant Staphylococcus aureus (MRSA) ATCC6538 bacterial cells. The results obtained from flow cytometry analysis showed that by increasing the concentration of rhamnolipid from 30 to 120 mg/mL, the cell viability decreased by about 70%, and the cell membrane permeability increased by approximately 20%. In fact, increasing rhamnolipid concentration was directly related to cell membrane permeability and inversely related to cell survival. Microtiter plate biofilm assay and laser scanning confocal microscopy analysis revealed that rhamnolipid, at a concentration of 60 mg/mL, exerts a reducing effect on the biofilm formation of Staphylococcus aureus. Real-time PCR analysis for monitoring the relative changes in the expression of agrA, agrC, icaA, and icaD genes involved in biofilm formation and related to the quorum-sensing pathway after treatment with rhamnolipid indicated a reduced expression level of these genes, as well as sortase A gene. The results of the present study deepen our knowledge regarding the use of microbial natural products as promising candidates for therapeutic applications.

Nanoscale Zeolitic Imidazolate Framework (ZIF)–8 in Cancer Theranostics: Current Challenges and Prospects

Simple Summary

The biomedical application of metal–organic frameworks in cancer theranostics has become a research hotspot with rapid progress. As a typical representative, ZIF–8 attracts increasing interest from researchers due to its good performance and potential. In this review, we updated recent discoveries on the ZIF–8–based nanoplatforms for cancer, discussed the problems in current research and the obstacles for clinical translation of ZIF–8, and also proposed an outlook on its future development.

Abstract

Cancer severely threatens human health and has remained the leading cause of disease–related death for decades. With the rapid advancement of nanomedicine, nanoscale metal–organic frameworks are believed to be potentially applied in the treatment and biomedical imaging for various tumors. Zeolite imidazole framework (ZIF)–8 attracts increasing attention due to its high porosity, large specific surface area, and pH–responsiveness. The designs and modifications of ZIF–8 nanoparticles, as well as the strategy of drug loading, demand a multifaceted and comprehensive understanding of nanomaterial features and tumor characteristics. We searched for studies on ZIF–8–based nanoplatforms in tumor theranostics on Web of Science from 2015 to 2022, mainly focused on the research published in the past 3 years, summarized the progress of their applications in tumor imaging and treatment, and discussed the favorable aspects of ZIF–8 nanoparticles for tumor theranostics as well as the future opportunities and potential challenges. As a kind of metal–organic framework material full of potential, ZIF–8 can be expected to be combined with more therapeutic systems in the future and continue to contribute to all aspects of tumor therapy and diagnosis.

Promising advances in nanobiotic-based formulations for drug specific targeting against multidrug-resistant microbes and biofilm-associated infections

Antimicrobial agents and alternative strategies to combat bacterial infections have become urgent due to the rapid development of multidrug-resistant bacteria caused by the misuse and overuse of antibiotics, as well as the ineffectiveness of antibiotics against difficult-to-treat infectious diseases. Nanobiotics is one of the strategies being explored to counter the increase in antibiotic-resistant bacteria. Nanobiotics are antibiotic molecules encapsulated in nanoparticles or artificially engineered pure antibiotics that are ≤ 100 nm in size in at least one dimension. Formulation scientists recognize nanobiotic delivery systems as an effective strategy to overcome the limitations associated with conventional antibiotic therapy. This review highlights the general mechanisms by which nanobiotics can be used to target resistant microbes and biofilm-associated infections. We focus on the design elements, properties, characterization, and toxicity assessment of organic nanoparticles, inorganic nanoparticle and molecularly imprinted polymer-based nano-formulations that can be designed to improve the efficacy of nanobiotic formulation.

Development of responsive chitosan-based hydrogels for the treatment of pathogen-induced skin infections

Vancomycin (Van) remains one of the first-line drugs for the treatment of wound infections caused by methicillin-resistant Staphylococcus aureus (MRSA). However, the unsatisfactory bioavailability of vancomycin alone has greatly limited its potential health benefits. Here a responsive chitosan-based hydrogel was developed as the delivery system which not only would reduce this side effect but also increase efficacy of vancomycin. The hydrogel was prepared by grafting chitosan and cinnamaldehyde-based thioacetal (CTA) together with ginipin (G) as the crosslinker. Upon exposure to reactive oxygen species which were enriched in the bacterial wound, the hydrogel can locally degrade and sustainably release the loaded vancomycin near the lesion to compete with the troubling MRSA. Compared with vancomycin alone, the chitosan-based hydrogel loaded with vancomycin demonstrated accelerated acute wound healing. This achievement reveals that this multi-functional hydrogel may be a promising drug-delivery device for improving the efficacy of local antibiotic therapy.

pH-Responsive hyaluronic acid-enveloped ZIF-8 nanoparticles for anti-atherosclerosis therapy

Nanomedicines represent new promising strategies for treating atherosclerosis (AS), because they enhance drug bioavailability and have lower side effects. Nevertheless, nanomedicines have several challenges with these advantages, including a limited circulation life, lack of precise targeting, and insufficient control of drug release. Accordingly, the development of drug delivery systems (DDSs) with abilities to enhance the payload delivery to the AS plaque lesion and to control drug release can boost the therapeutic efficacy and safety for AS treatment. Herein, we employed a one-step self-assembly approach for effectively encapsulating the anti-AS drug simvastatin (SIM) in zeolitic imidazolate framework-8 (ZIF-8) (SIM/ZIF-8), and then coated it with hyaluronic acid (HA) to fabricate the SIM/ZIF-8@HA nanoplatform. The resulting nanoplatform could efficiently accumulate in plaque regions through the specific recognition between HA and CD44. Meanwhile, the acid environment breaks down ZIF-8 to release SIM. The in vitro and in vivo experiments demonstrated that SIM/ZIF-8@HA could inhibit the proliferation of smooth muscle cells and have good biocompatibility. Moreover, SIM/ZIF-8@HA can effectively suppress the development of AS plaques without any considerable side effects in mice treatments. The findings revealed that SIM/ZIF-8@HA may be a promising nanomedicine for safe and efficient anti-AS applications.

Exploring the applications of hyaluronic acid-based nanoparticles for diagnosis and treatment of bacterial infections

Hyaluronic acid (HA) has become a topic of significant interest in drug delivery research due to its excellent properties, including biosafety, biodegradability, and nonimmunogenicity. Moreover, due to its ease of modification, HA can be used to prepare several HA‐based nanosystems using various approaches. These approaches involve conjugating/grafting of hydrophobic moieties, polyelectrolytes complexation with cationic polymers, or surface modification of various nanoparticles using HA. These nanoparticles are able to selectively deliver antibacterial drugs or diagnostic molecules into the site of infections. In addition, HA can bind with overexpressed cluster of differentiation 44 (CD44) receptors in macrophages and also can be degraded by a family of enzymes called hyaluronidase (HAase) to release drugs or molecules. By binding with these receptors or being degraded at the infection site by HAase, HA‐based nanoparticles allow enhanced and targeted antibacterial delivery. Herein, we present a comprehensive and up‐to‐date review that highlights various techniques of preparation of HA‐based nanoparticles that have been reported in the literature. Furthermore, we also discuss and critically analyze numerous types of HA‐based nanoparticles that have been employed in antibacterial delivery to date. This article offers a critical overview of the potential of HA‐based nanoparticles to overcome the challenges of conventional antibiotics in the treatment of bacterial infections. Moreover, this review identifies further avenues of research for developing multifunctional and biomimetic HA‐based nanoparticles for the treatment, prevention, and/or detection of pathogenic bacteria.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Advances in Nanostructures for Antimicrobial Therapy

Microbial infections caused by a variety of drug-resistant microorganisms are more common, but there are fewer and fewer approved new antimicrobial chemotherapeutics for systemic administration capable of acting against these resistant infectious pathogens. Formulation innovations of existing drugs are gaining prominence, while the application of nanotechnologies is a useful alternative for improving/increasing the effect of existing antimicrobial drugs. Nanomaterials represent one of the possible strategies to address this unfortunate situation. This review aims to summarize the most current results of nanoformulations of antibiotics and antibacterial active nanomaterials. Nanoformulations of antimicrobial peptides, synergistic combinations of antimicrobial-active agents with nitric oxide donors or combinations of small organic molecules or polymers with metals, metal oxides or metalloids are discussed as well. The mechanisms of actions of selected nanoformulations, including systems with magnetic, photothermal or photodynamic effects, are briefly described.

Nanoantibiotics to fight multidrug resistant infections by Gram-positive bacteria: hope or reality?

The spread of antimicrobial resistance in Gram-positive pathogens represents a threat to human health. To counteract the current lack of novel antibiotics, alternative antibacterial treatments have been increasingly investigated. This review covers the last decade's developments in using nanoparticles as carriers for the two classes of frontline antibiotics active on multidrug-resistant Gram-positive pathogens, i.e., glycopeptide antibiotics and daptomycin. Most of the reviewed papers deal with vancomycin nanoformulations, being teicoplanin- and daptomycin-carrying nanosystems much less investigated. Special attention is addressed to nanoantibiotics used for contrasting biofilm-associated infections. The status of the art related to nanoantibiotic toxicity is critically reviewed.

Embedding an extraordinary amount of gemifloxacin antibiotic in ZIF-8 framework with one-step synthesis and measurement of its H2O2-sensitive release and potency against infectious bacteria

GEM@ZIF-8 has DLC = 69.82% and DLE = 89.03%, with controlled release dependent on H2O2 concentration, and it shows significant antibacterial activity.

Construction of a Multifunctional Nano-Scale Metal-Organic Framework-Based Drug Delivery System for Targeted Cancer Therapy

The antitumor activity of triptolide (TP) has received widespread attention, although its toxicity severely limits its clinical application. Therefore, the design of a targeted drug delivery system (TDDS) has important application prospects in tumor treatment. Metal–organic frameworks (MOFs), with high drug-carrying capacity and good biocompatibility, have aroused widespread interest for drug delivery systems. Herein, folic acid (FA) and 5-carboxylic acid fluorescein (5-FAM) were used to modify Fe-MIL-101 to construct a functionalized nano-platform (5-FAM/FA/TP@Fe-MIL-101) for the targeted delivery of the anti-tumor drug triptolide and realize in vivo fluorescence imaging. Compared with Fe-MIL-101, functionalized nanoparticles not only showed better targeted therapy efficiency, but also reduced the systemic toxicity of triptolide. In addition, the modification of 5-FAM facilitated fluorescence imaging of the tumor site and realized the construction of an integrated nano-platform for fluorescence imaging and treatment. Both in vitro and in vivo studies of functionalized nanoparticles have demonstrated excellent fluorescence imaging and synergistic targeting anticancer activity with negligible systemic toxicity. The development of functional nano-platform provides new ideas for the design of MOF-based multifunctional nano-drug delivery system, which can be used for precise treatment of tumor.

Prolonged release and shelf-life of anticoagulant sulfated polysaccharides encapsulated with ZIF-8

Natural active polysaccharides are attracting increased attention from pharmaceutical industries for their valuable biological activities. However, the application of polysaccharides has been restricted due to their relatively large molecular weight, complex structure, and instability. Metal-organic frameworks (MOFs) have emerged to help deliver cargo to specific locations, achieving the objectives of eliminating the potential damage to the body, protecting the drugs, and improving therapeutic effectiveness. Here, a pH-responsive zeolitic imidazolate framework (ZIF-8) was synthesized to encapsulated three sulfated polysaccharides (heparin, fucan sulfate, fucosylated chondroitin sulfate) and a non-sulfated polysaccharide, hyaluronic acid. The resulting polysaccharides@ZIF-8 biocomposites showed differences in terms of morphology, particle size, encapsulation, and release efficiency. These biocomposites retained antithrombotic activity and the framework ZIF-8 effectively protected these polysaccharides from degradation and prolonged shelf-life of the anticoagulants from the unfavorable environment.

Hyaluronic acid coating on the surface of curcumin-loaded ZIF-8 nanoparticles for improved breast cancer therapy: An in vitro and in vivo study

Despite developments in surgery and chemotherapy, effective treatment of breast cancer is still an urgent problem owing to recurrence and metastasis. By combining the advantages of curcumin (Cur), zeolitic imidazolate framework-8 nanoparticles (ZIF-8), and hyaluronic acid (HA) in breast cancer therapy, Cur-loaded and HA-coated ZIF-8 (Cur@ZIF-8@HA) were synthesized using a method based on the pH-dependent solubility of Cur and the electrostatic interactions between zinc ions and carboxyl groups of HA. Cur@ZIF-8 were also prepared as a control group. Comprehensive comparisons of the physicochemical properties and anticancer activities of Cur@ZIF-8@HA and Cur@ZIF-8 were conducted. The results indicated that the degradation of Cur during the synthesis of Cur@ZIF-8 was negligible. The obtained Cur@ZIF-8 and Cur@ZIF-8@HA were truncated cubes with hydrodynamic diameters of 174 and 217 nm, respectively. Cur@ZIF-8@HA possessed better stability during storage in different media, a slower drug release rate under neutral and acidic conditions, and a greater inhibitory effect on breast cancer than Cur@ZIF-8. For 4T1 cells, treatment using Cur@ZIF-8@HA induced more cellular uptake and higher cytotoxicity, accompanied by higher lactate dehydrogenase release, cell cycle arrest in G2/M and S phases, production of reactive oxygen species, and apoptosis. In 4T1 tumor-bearing mice models, Cur@ZIF-8@HA showed a stronger inhibitory effect on tumor growth and pulmonary metastasis. Therefore, Cur@ZIF-8@HA might hold great potential as an agent for the effective therapy of breast cancer.

Core–shell ZIF-8@polydopamine nanoparticles obtained by mitigating the polydopamine coating induced self-etching of MOFs: prototypical metal ion reservoirs for sticking to and killing bacteria

ZIF-8@PDA nanoparticles can work as metal ion reservoirs that locally release metal ions to kill bacteria after sticking to them.

BMP-6 carrying metal organic framework-embedded in bioresorbable electrospun fibers for enhanced bone regeneration

Biomolecule carrier structures have attracted substantial interest owing to their potential utilizations in the field of bone tissue engineering. In this study, MOF-embedded electrospun fiber scaffold for the controlled release of BMP-6 was developed for the first time, to enrich bone regeneration efficacy. The scaffolds were achieved by first, one-pot rapid crystallization of BMP-6 encapsulated ZIF-8 nanocrystals-as a novel carrier for growth factor molecules- and then electrospinning of the blending solution composed of poly (ε-caprolactone) and BMP-6 encapsulated ZIF-8 nanocrystals. BMP-6 molecule encapsulation efficiency for ZIF-8 nanocrystals was calculated as 98%. The in-vitro studies showed that, the bioactivity of BMP-6 was preserved and the release lasted up to 30 days. The release kinetics fitted the Korsmeyer-Peppas model exhibiting a pseudo-Fickian behavior. The in-vitro osteogenesis studies revealed the superior effect of sustained release of BMP-6 towards osteogenic differentiation of MC3T3-E1 pre-osteoblasts. In-vivo studies also revealed that the sustained slow release of BMP-6 was responsible for the generation of well-mineralized, new bone formation in a rat cranial defect. Our results proved that; MOF-carriers embedded in electrospun scaffolds can be used as an effective platform for bone regeneration in bone tissue engineering applications. The proposed approach can easily be adapted for various growth factor molecules for different tissue engineering applications.