Enhancing osteoregenerative potential of biphasic calcium phosphates by using bioinspired ZIF8 coating

Zeolite imidazolate framework-8 in bone regeneration: A systematic review

Zeolite imidazolate framework-8 (ZIF-8) is a biomaterial that has been increasingly studied in recent years. It has several applications such as bone regeneration, promotion of angiogenesis, drug loading, and antibacterial activity, and exerts multiple effects to deal with various problems in the process of bone regeneration. This systematic review aims to provide an overview of the applications and effectiveness of ZIF-8 in bone regeneration. A search of papers published in the PubMed, Web of Science, Embase, and Cochrane Library databases revealed 532 relevant studies. Title, abstract, and full-text screening resulted in 39 papers being included in the review, including 39 in vitro and 22 animal studies. Appropriate concentrations of nano ZIF-8 can promote cell proliferation and osteogenic differentiation by releasing Zn2+ and entering the cell, whereas high doses of ZIF-8 are cytotoxic and inhibit osteogenic differentiation. In addition, five studies confirmed that ZIF-8 exhibits good vasogenic activity. In all in vivo experiments, nano ZIF-8 promoted bone formation. These results indicate that, at appropriate concentrations, materials containing ZIF-8 promote bone regeneration more than materials without ZIF-8, and with characteristics such as promoting angiogenesis, drug loading, and antibacterial activity, it is expected to show promising applications in the field of bone regeneration. STATEMENT OF SIGNIFICANCE: This manuscript reviewed the use of ZIF-8 in bone regeneration, clarified the biocompatibility and effectiveness in promoting bone regeneration of ZIF-8 materials, and discussed the possible mechanisms and factors affecting its promotion of bone regeneration. Overall, this study provides a better understanding of the latest advances in the field of bone regeneration of ZIF-8, serves as a design guide, and contributes to the design of future experimental studies.

Application of Zeolites and Zeolitic Imidazolate Frameworks in Dentistry-A Narrative Review

Zeolites and zeolitic imidazolate frameworks (ZIFs) are crystalline aluminosilicates with porous structure, which are closely linked with nanomaterials. They are characterized by enhanced ion exchange capacity, physical-chemical stability, thermal stability and biocompatibility, making them a promising material for dental applications. This review aimed to provide an overview of the application of zeolites and ZIFs in dentistry. The common zeolite compounds for dental application include silver zeolite, zinc zeolite, calcium zeolite and strontium zeolite. The common ZIFs for dental application include ZIF-8 and ZIF-67. Zeolites and ZIFs have been employed in various areas of dentistry, such as restorative dentistry, endodontics, prosthodontics, implantology, periodontics, orthodontics and oral surgery. In restorative dentistry, zeolites and ZIFs are used as antimicrobial additives in dental adhesives and restorative materials. In endodontics, zeolites are used in root-end fillings, root canal irritants, root canal sealers and bone matrix scaffolds for peri-apical diseases. In prosthodontics, zeolites can be incorporated into denture bases, tissue conditioners, soft denture liners and dental prostheses. In implantology, zeolites and ZIFs are applied in dental implants, bone graft materials, bone adhesive hydrogels, drug delivery systems and electrospinning. In periodontics, zeolites can be applied as antibacterial agents for deep periodontal pockets, while ZIFs can be embedded in guided tissue regeneration membranes and guided bone regeneration membranes. In orthodontics, zeolites can be applied in orthodontic appliances. Additionally, for oral surgery, zeolites can be used in oral cancer diagnostic marker membranes, maxillofacial prosthesis silicone elastomer and tooth extraction medicines, while ZIFs can be incorporated to osteogenic glue or used as a carrier for antitumour drugs. In summary, zeolites have a broad application in dentistry and are receiving more attention from clinicians and researchers.

In vivo evaluation of bone regeneration using ZIF8-modified polypropylene membrane in rat calvarium defects

AIM

The profound potential of zeolitic imidazolate framework 8 (ZIF8) thin film for inducing osteogenesis has been previously established under in vitro conditions. As the next step towards the clinical application of ZIF8-modified substrates in periodontology, this in vivo study aimed to evaluate the ability of the ZIF8 crystalline layer to induce bone regeneration in an animal model defect.

MATERIALS AND METHODS

Following the mechanical characterization of the membranes and analysing the in vitro degradation of the ZIF8 layer, in vivo bone regeneration was evaluated in a critical-sized (5-mm) rat calvarial bone defect model. For each animal, one defect was randomly covered with either a polypropylene (PP) or a ZIF8-modified membrane (n = 7 per group), while the other defect was left untreated as a control. Eight weeks post surgery, bone formation was assessed by microcomputed tomography scanning, haematoxylin and eosin staining and immunohistochemical analysis.

RESULTS

The ZIF8-modified membrane outperformed the PP membrane in terms of mechanical properties and revealed a trace Zn+2 release. Results of in vivo evaluation verified the superior barrier function of the ZIF8-coated membrane compared with pristine PP membrane. Compared with the limited marginal bone formation in the control and PP groups, the defect area was almost filled with mature bone in the ZIF8-coated membrane group.

CONCLUSIONS

Our results support the effectiveness of the ZIF8-coated membrane as a promising material for improving clinical outcomes of guided bone regeneration procedures, without using biological components.

Integrated MOF-74 Coatings on Magnesium for Corrosion Control, Cytocompatibility, and Antibacterial Properties

Biodegradable Mg and its alloys can degrade safely in vivo without toxicity. The major bottleneck inhibiting their clinical use is the high corrosion rate, which leads to the loss of mechanical integrity prematurely and bad biocompatibility. One ideal strategy is the modification with anticorrosive and bioactive coatings. Numerous metal-organic framework (MOF) membranes show satisfactory anticorrosion performance and biocompatibility. In this study, MOF-74 membranes are prepared on an NH₄TiOF₃ (NTiF) layer-modified Mg matrix, fabricating integrated bilayer coatings (MOF-74/NTiF) for corrosion control, cytocompatibility, and antibacterial properties. The inner NTiF layer serves as the primary protection for the Mg matrix and a stable surface for the growth of MOF-74 membranes. The outer MOF-74 membranes further enhance corrosion protection, whose crystals and thicknesses can be adjusted for different protective effects. Owing to superhydrophilic, micro-nanostructural, and nontoxic decomposition products, MOF-74 membranes significantly promote cell adhesion and proliferation, showing excellent cytocompatibility. Utilizing the decomposition of MOF-74 to generate the products of Zn²⁺ and 2,5-dihydroxyterephthalic acid can effectively inhibit Escherichia coli and Staphylococcus aureus, displaying highly efficient antibacterial properties. The research may shed valuable strategies for MOF-based functional coatings in the applications of biomedicine fields.

Zeolites: A series of promising biomaterials in bone tissue engineering

As an important worldwide medical issue, bone defect exhibits a variety of physical and psychological consequences on sufferers. Some features of clinical treatments including bone grafting and limb shortening are not satisfactory. Recently, bone tissue engineering has been considered as the most effective approach to dealing with the issue of bone deformities. Meanwhile, a variety of biomaterials have been rationally designed and created for the bone regeneration and tissue repairing. Among all these admirable biomaterials for bone remodeling, zeolite-based materials can serve as efficient scaffold candidates with excellent osteo-inductivity. In addition, the porous nature and high biocompatibility of zeolites endow them with the ability as ideal substrates for cell adhesion and proliferation. More importantly, zeolites are investigated as potential coating materials for implants because they have been proven to increase osteo-conductivity and aid in local elastic modeling. Last but not least, zeolites can also be used to treat bone disorders and act as dietary supplements during the practical applications. Accordingly, numerous benefits of zeolite prompt us to summarize their recent biomedical progress including but not limited to the distinguishing characteristics, broad classifications, as well as promising usages in bone tissue engineering.

Surgical safety checklists for dental implant surgeries-a scoping review

OBJECTIVES

In both elective surgeries and aviation, a reduction of complications can be expected by paying attention to the so-called human factors. Checklists are a well-known way to overcome some of these problems. We aimed to evaluate the current evidence regarding the use of checklists in implant dentistry.

METHODS

An electronic literature search was conducted in the following databases: CINHAL, Medline, Web of Science, and Cochrane Library until March 2022. Based on the results and additional literature, a preliminary checklist for surgical implant therapy was designed.

RESULTS

Three publications dealing with dental implants and checklists were identified. One dealt with the use of a checklist in implant dentistry and was described as a quality assessment study. The remaining two studies offered suggestions for checklists based on literature research and expert opinion.

CONCLUSIONS

Based on our results, the evidence for the use of checklists in dental implantology is extremely low. Considering the great potential, it can be stated that there is a need to catch up. While creating a new implant checklist, we took care of meeting the criteria for high-quality checklists. Future controlled studies will help to place it on a broad foundation.

CLINICAL RELEVANCE

Checklists are a well-known way to prevent complications. They are especially established in aviation, but many surgical specialties and anesthesia adopt this successful concept. As implantology has become one of the fastest-growing areas of dentistry, it is imperative that checklists become an integral part of it.

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

Metal-organic frameworks (MOFs) have recently emerged as a useful class of nanostructures with well-suited characteristics for drug delivery applications, due to the high surface area and pore size for efficient loading. Despite their use as a nano-carrier for controlled delivery of various types of drugs, the inherent osteo-conductive properties have stolen a great attention as a growing area of investigation. Here, we evaluated the double function of UiO-66 MOF structure as a carrier for fosfomycin antibiotic and also as an osteogenic differentiation promoter when introduced in 3D chitosan scaffolds, for the first time. Our results revealed that the wet-spun chitosan scaffolds containing fosfomycin loaded UiO-66 nanocrystals (CHI/UiO-66/FOS) possessed fiber mesh structure with integrated micro-scale fibers and increased mechanical strength. In vitro antibacterial studies indicated that CHI/UiO-66/FOS scaffolds showed bactericidal activity against Staphylococcus aureus. Moreover, the scaffolds were biocompatible to MC3T3-E1 pre-osteoblasts and significantly up-regulated the expression of osteogenesis-related genes and facilitated the extracellular matrix mineralization, in vitro. Taken together, our results demonstrate UiO-66 MOFs can present double functionality and CHI/UiO-66/FOS scaffolds hold a significant potential to be further explored as an alternative approach in treating infected bone defects like osteomyelitis.