UiO-66 metal-organic framework as a double actor in chitosan scaffolds: Antibiotic carrier and osteogenesis promoter

Bifunctional mesoporous HMUiO-66-NH2 nanoparticles for bone remodeling and ROS scavenging in periodontitis therapy

Periodontal bone defects represent an irreversible consequence of periodontitis associated with reactive oxygen species (ROS). However, indiscriminate removal of ROS proves to be counterproductive for tissue repair and insufficient for addressing existing bone defects. In the treatment of periodontitis, it is crucial to rationally alleviate local ROS while simultaneously promoting bone regeneration. In this study, Zr-based large-pore hierarchical mesoporous metal-organic framework (MOF) nanoparticles (NPs) HMUiO-66-NH2 were successfully proposed as bifunctional nanomaterials for bone regeneration and ROS scavenging in periodontitis therapy. HMUiO-66-NH2 NPs demonstrated outstanding biocompatibility both in vitro and in vivo. Significantly, these NPs enhanced the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) under normal and high ROS conditions, upregulating osteogenic gene expression and mitigating oxidative stress. Furthermore, in vivo imaging revealed a gradual degradation of HMUiO-66-NH2 NPs in periodontal tissues. Local injection of HMUiO-66-NH2 effectively reduced bone defects and ROS levels in periodontitis-induced C57BL/6 mice. RNA sequencing highlighted that differentially expressed genes (DEGs) are predominantly involved in bone tissue development, with notable upregulation in Wnt and TGF-β signaling pathways. In conclusion, HMUiO-66-NH2 exhibits dual functionality in alleviating oxidative stress and promoting bone repair, positioning it as an effective strategy against bone resorption in oxidative stress-related periodontitis.

Application of metal-organic framework materials in regenerative medicine

In the past few decades, scaffolds manufactured from composite or hybrid biomaterials of natural or synthetic origin have made great strides in enhancing wound healing and repairing fractures and pathological bone loss. However, the prevailing use of such scaffolds in tissue engineering is accompanied by numerous constraints, including low mechanical stability, poor biological activity, and impaired cell proliferation and differentiation. The performance of scaffolds in wound and bone tissue engineering may be enhanced by some modifications in the synthesis of nanoscale metal-organic framework (nano-MOF) scaffolds. Nano-MOFs have attracted researchers' attention in recent years due to their distinctive features, which include tenability, biocompatibility, good mechanical stability, and ultrahigh surface area. The biological properties of scaffolds are enhanced and tissue regeneration is facilitated by the introduction of nano-MOFs. Moreover, the physicochemical characteristics, drug loading, and ion release capacities of the scaffolds are improved by the nanoscale structure and topological features of nano-MOFs, which also control stem cell differentiation, proliferation, and attachment. This review provides further comprehensive detail about the most recent uses of nano-MOFs in tissue engineering. The distinct characteristics of nano-MOFs are explored in enhancing tissue repair, wound healing, osteoinduction, and bone conductivity. Significant attributes include high antibacterial activity, substantial drug-loading capacity, and the ability to regulate drug release. Finally, this discussion addresses the obstacles, clinical impediments, and considerations encountered in the application of these nanomaterials to diverse scaffolds, tissue-mimicking structures, dressings, fillers, and implants for bone tissue repair and wound healing.

A grafting approach for nisin-chitosan bio-based antibacterial films: preparation and characterization

Nisin is a bacteriocin produced by Gram-positive lactic acid bacterium,Lactococcus lactisand currently recognized in the Generally Recognızed as Safe (GRAS) category due to its non-toxicity. Herein, nisin has been grafted to chitosan structure to obtain natural bio-active films with enhanced antibacterial activity. Grafting was performed using ethyl ester lysine diisocyanate and dimer fatty acid-based diisocyanate (DDI); two different close to fully bio-based diisocyanates and Disuccinimidyl suberate; a homo-bifunctional molecule acting as a crosslinker between amino groups. The grafting process allowed the chemical immobilization of nisin to chitosan structure. Physicochemical characterization studies showed the successful grafting of nisin. The antibacterial activity againstStaphylococcus aureuswas evident for all nisin modified chitosan films and best pronounced when DDI was used as a crosslinker with a maximum zone of inhibition of ∼13 mm. All nisin grafted chitosan films were cytocompatible and the cell viability of L929 fibroblasts were >80% pointing out the non-toxic structure. Considering the results of the presented study, bio-based diisocyanates and homo-bifunctional crosslinkers are effective molecules in synthesis of nisin grafted chitosan structures and the new chitosan based antibacterial biopolymers obtained after nisin modification come forward as promising non-toxic and bioactive candidates to be applied in medical devices, implants, and various food coating products.

Propelling Minimally Invasive Tissue Regeneration With Next-Era Injectable Pre-Formed Scaffolds

The growing aging population, with its associated chronic diseases, underscores the urgency for effective tissue regeneration strategies. Biomaterials play a pivotal role in the realm of tissue reconstruction and regeneration, with a distinct shift toward minimally invasive (MI) treatments. This transition, fueled by engineered biomaterials, steers away from invasive surgical procedures to embrace approaches offering reduced trauma, accelerated recovery, and cost-effectiveness. In the realm of MI tissue repair and cargo delivery, various techniques are explored. While in situ polymerization is prominent, it is not without its challenges. This narrative review explores diverse biomaterials, fabrication methods, and biofunctionalization for injectable pre-formed scaffolds, focusing on their unique advantages. The injectable pre-formed scaffolds, exhibiting compressibility, controlled injection, and maintained mechanical integrity, emerge as promising alternative solutions to in situ polymerization challenges. The conclusion of this review emphasizes the importance of interdisciplinary design facilitated by synergizing fields of materials science, advanced 3D biomanufacturing, mechanobiological studies, and innovative approaches for effective MI tissue regeneration.

Evaluation of the Antibacterial, Anti-Inflammatory, And Bone-Promoting Capacity of UiO-66 Loaded with Thymol or Carvacrol

Oral infectious diseases have a significant impact on the health of oral and maxillofacial regions, as well as the overall well-being of individuals. Carvacrol and thymol, two isomers known for their effective antibacterial and anti-inflammatory properties, have gained considerable attention in the treatment of oral infectious diseases. However, their application as topical drugs for oral use is limited due to their poor physical and chemical stability. UiO-66, a metal-organic framework based on zirconium ion (Zr4+), exhibits high drug loading capability. Carvacrol and thymol were efficiently loaded onto UiO-66 with loading rates of 79.60 ± 0.71% and 79.65 ± 0.76%, respectively. The release rates of carvacrol and thymol were 77.82 ± 0.87% and 76.51 ± 0.58%, respectively, after a period of 72 h. Moreover, Car@UiO-66 and Thy@UiO-66 demonstrated excellent antibacterial properties against Candida albicans, Escherichia coli, and Staphylococcus aureus with minimum bactericidal concentrations (MBC) of 0.313 mg/mL, 0.313 mg/mL, and 1.25 mg/mL, respectively. Furthermore, based on the results of the CCK8 cytotoxicity assay, even at concentrations as high as 1.25 mg/mL, Car@UiO-66 and Thy@UiO-66 exhibited excellent biocompatibility with a relative cell survival rate above 50%. These findings suggest that Car@UiO-66 and Thy@UiO-66 possess favorable biocompatibility properties without significant toxicity towards periodontal membrane cells. Additionally, in vivo studies confirmed the efficacy of Car@UiO-66and Thy@UiO-66 in reducing inflammation, promoting bone formation through inhibition of TNF-a and IL6 expression, enhancement of IL10 expression, and acceleration of bone defect healing. Therefore, the unique combination of antibacterial, anti-inflammatory, and osteogenic properties make Car@UiO-66 and Thy@Ui O-66 promising candidates for the treatment of oral infectious diseases and repairing bone defects.

Synthesis of two Fluorescent Complexes and Their use as Multifunctional Nanomedicine Carriers for Rhabdomyosarcoma Treatment

This study focuses on the design and synthesis of two novel coordination polymers (CPs), named 1 and 2, with excellent fluorescent properties. Their structures were characterized by X-ray single-crystal diffraction, revealing that both materials exhibit promising fluorescence performance, indicating their potential as fluorescent detection tools. Additionally, 1 was chosen to be combined with chitosan (CS), resulting in the successful fabrication of a biodegradable and non-toxic efficient drug carrier, termed CS-1@Cisplatin. This carrier possesses a large surface area and good solubility, enabling sustained drug release to target cells. Given that CXC motif chemokine receptor type 4 (CXCR4) is a key marker gene highly expressed in Rhabdomyosarcoma (RMS) cells and tissues, RMS was chosen as the biological model for testing. The results demonstrated that CS-1@Cisplatin effectively inhibited the invasiveness of RMS cells by significantly suppressing CXCR4 expression. Therefore, the system shows great potential for applications in RMS treatment, biometrics, and drug delivery, particularly in its unique advantage of targeting RMS by inhibiting the key marker gene CXCR4.

Metal-Organic Framework-Based Nanomaterials for Regulation of the Osteogenic Microenvironment

As the global population ages, bone diseases have become increasingly prevalent in clinical settings. These conditions often involve detrimental factors such as infection, inflammation, and oxidative stress that disrupt bone homeostasis. Addressing these disorders requires exogenous strategies to regulate the osteogenic microenvironment (OME). The exogenous regulation of OME can be divided into four processes: induction, modulation, protection, and support, each serving a specific purpose. To this end, metal-organic frameworks (MOFs) are an emerging focus in nanomedicine, which show tremendous potential due to their superior delivery capability. MOFs play numerous roles in OME regulation such as metal ion donors, drug carriers, nanozymes, and photosensitizers, which have been extensively explored in recent studies. This review presents a comprehensive introduction to the exogenous regulation of OME by MOF-based nanomaterials. By discussing various functional MOF composites, this work aims to inspire and guide the creation of sophisticated and efficient nanomaterials for bone disease management.

Chitosan-based films grafted with citrus waste-derived antifungal agents: An innovative and sustainable approach to enhance post-harvest preservation of citrus fruit

This paper reports the synthesis, characterization, and properties of chitosan films (CHI) grafted with a natural antifungal agent with the aim of developing active films of natural origin to prevent post-harvest losses of citrus fruit. The antifungal agent was prepared by fermentation using lemon peel (AntiFun-LM), a citrus waste, and grafted on chitosan using different coupling agents (CHI/AntiFun-LM). Bioactive films were prepared by solvent casting. FTIR-ATR and ToF-SIMS analyses provided compelling evidence of the successful grafting process. TGA-DSC demonstrated that the films are stable after grafting. SEM studies showed the continuous and compact surface of the films. WCA measurements proved that CHI/AntiFun-LM films are more hydrophilic than CHI films. Moreover, the CHI/AntiFun-LM films showed stronger UV shielding effect when compared to CHI. The biological evaluation demonstrated that CHI/AntiFun-LM films gained considerable antifungal properties against most fungi responsible for post-harvest decay. Cytotoxicity tests showed that CHI/AntiFun-LM films did not cause any toxic effect against L929 fibroblasts. This study highlights the great potential of chemical grafting of antifungal agents produced from citrus waste to chitosan and preparation of natural-based films to act as a powerful alternative in post-harvest protection of citrus fruit in a perspective of circular economy.

Synergistic effect of hierarchical topographic structure on 3D-printed Titanium scaffold for enhanced coupling of osteogenesis and angiogenesis

The significance of the osteogenesis-angiogenesis relationship in the healing process of bone defects has been increasingly emphasized in recent academic research. Surface topography plays a crucial role in guiding cellular behaviors. Metal-organic framework (MOF) is an innovative biomaterial with nanoscale structural and topological features, enabling the modulation of scaffold physicochemical properties. This study involved the loading of varying quantities of UiO-66 nanocrystals onto alkali-heat treated 3D-printed titanium scaffolds, resulting in the formation of hierarchical micro/nano topography named UiO-66/AHTs. The physicochemical properties of these scaffolds were subsequently characterized. Furthermore, the impact of these scaffolds on the osteogenic potential of BMSCs, the angiogenic potential of HUVECs, and their intercellular communication were investigated. The findings of this study indicated that 1/2UiO-66/AHT outperformed other groups in terms of osteogenic and angiogenic induction, as well as in promoting intercellular crosstalk by enhancing paracrine effects. These results suggest a promising biomimetic hierarchical topography design that facilitates the coupling of osteogenesis and angiogenesis.

Metal-organic frameworks functionalized biomaterials for promoting bone repair

Bone defects induced by bone trauma, tumors and osteoarthritis greatly affect the life quality and health of patients. The biomaterials with numerous advantages are becoming the most preferred options for repairing bone defects and treating orthopedic diseases. However, their repairing effects remains unsatisfactory, especially in bone defects suffering from tumor, inflammation, and/or bacterial infection. There are several strategies to functionalize biomaterials, but a more general and efficient method is essential for accomplishing the functionalization of biomaterials. Possessing high specific surface, high porosity, controlled degradability and variable composition, metal-organic frameworks (MOFs) materials are inherently advantageous for functionalizing biomaterials, with tremendous improvements having been achieved. This review summarizes recent progresses in MOFs functionalized biomaterials for promoting bone repair and therapeutic effects. In specific, by utilizing various properties of diverse MOFs materials, integrated MOFs functionalized biomaterials achieve enhanced bone regeneration, antibacterial, anti-inflammatory and anti-tumor functions. Finally, the summary and prospects of on the development of MOFs-functionalized biomaterials for promoting bone repair were discussed.

Trends and challenges in the development of bio-based barrier coating materials for paper/cardboard food packaging; a review

Currently, petroleum-based synthetic plastics are used as a key barrier material in the paper-based packaging of several food and nonfood goods. This widespread usage of plastic as a barrier lining is not only harmful to human and marine health, but it is also polluting the ecosystem. Researchers and food manufacturers are focused on biobased alternatives because of its numerous advantages, including biodegradability, biocompatibility, non-toxicity, and structural flexibility. When used alone or in composites/multilayers, these biobased alternatives provide strong barrier qualities against grease, oxygen, microbes, air, and water. According to the most recent literature reports, biobased polymers for barrier coatings are having difficulty breaking into the business. Technological breakthroughs in the field of bioplastic production and application are rapidly evolving, proffering new options for academics and industry to collaborate and develop sustainable packaging solutions. Existing techniques, such as multilayer coating of nanocomposites, can be improved further by designing them in a more systematic manner to attain the best barrier qualities. Modified nanocellulose, lignin nanoparticles, and bio-polyester are among the most promising future candidates for nanocomposite-based packaging films with high barrier qualities. In this review, the state-of-art and research advancements made in biobased polymeric alternatives such as paper and board barrier coating are summarized. Finally, the existing limitations and potential future development prospects for these biobased polymers as barrier materials are reviewed.