Bone Tissue Disorders: Healing Through Coordination Chemistry

Advances in metal-organic frameworks for optically selective alkaline phosphatase activity monitoring: a perspective

The study of Metal-Organic Frameworks (MOFs) has gained significant momentum due to their remarkable properties, including adjustable pore sizes, extensive surface area, and customizable compositions, which have urged scientists to investigate their applicability in pertinent societal issues such as water absorption, environmental remediation, and sensor technology. MOFs have the ability to transport and detect specific biomolecules, including proteins. One such biomolecule is alkaline phosphatase (ALP) that can be influenced by various diseases and can lead to severe consequences when its regulation is disrupted. The porous nature of MOFs and their tunable nature allows them to selectively adsorb, interact directly or indirectly with ALP. This ultimately influences the electronic and optical properties of the MOF, leading to measurable changes. Early detection and continuous monitoring of ALP play a crucial role in the use of an effective treatment, and recent studies have shown that MOFs are effective in detecting alkaline phosphatases. This manuscript offers a thorough examination of the potential biomedical applications of MOFs for monitoring alkaline phosphatase and envisions possible future trends in this field.

Hybrid Hydroxyapatite-Metal Complex Materials Derived from Amino Acids and Nucleobases

Calcium phosphates (CaPs) and their substituted derivatives encompass a large number of compounds with a vast presence in nature that have aroused a great interest for decades. In particular, hydroxyapatite (HAp, Ca10(OH)2(PO4)6) is the most abundant CaP mineral and is significant in the biological world, at least in part due to being a major compound in bones and teeth. HAp exhibits excellent properties, such as safety, stability, hardness, biocompatibility, and osteoconductivity, among others. Even some of its drawbacks, such as its fragility, can be redirected thanks to another essential feature: its great versatility. This is based on the compound's tendency to undergo substitutions of its constituent ions and to incorporate or anchor new molecules on its surface and pores. Thus, its affinity for biomolecules makes it an optimal compound for multiple applications, mainly, but not only, in biological and biomedical fields. The present review provides a chemical and structural context to explain the affinity of HAp for biomolecules such as proteins and nucleic acids to generate hybrid materials. A size-dependent criterium of increasing complexity is applied, ranging from amino acids/nucleobases to the corresponding macromolecules. The incorporation of metal ions or metal complexes into these functionalized compounds is also discussed.

Metal-Organic Frameworks as Sensors for Human Amyloid Diseases

Metal-organic frameworks (MOFs) are versatile compounds with emergent applications in the fabrication of biosensors for amyloid diseases. They hold great potential in biospecimen protection and unprecedented probing capabilities for optical and redox receptors. In this Review, we summarize the main methodologies employed in the fabrication of MOF-based sensors for amyloid diseases and collect all available data in the literature related to their performance (detection range, limit of detection, recovery, time of analysis, among other parameters). Nowadays, MOF sensors have evolved to a point where they can, in some cases, outperform technologies employed in the detection of several amyloid biomarkers (amyloid β peptide, α-synuclein, insulin, procalcitonin, and prolactin) present in biological fluids, such as cerebrospinal fluid and blood. A special emphasis has been given by researchers on Alzheimer's disease monitoring to the detriment of other amyloidosis that are underexploited despite their societal relevance (e.g., Parkinson's disease). There are still important obstacles to overcome in order to selectively detect the various peptide isoforms and soluble amyloid species associated with Alzheimer's disease. Furthermore, MOF contrast agents for imaging peptide soluble oligomers in living humans are also scarce (if not nonexistent), and action in this direction is unquestionably required to clarify the contentious link between the amyloidogenic species and the disease, guiding research toward the most promising therapeutic strategies.

Porphyrin NanoMetal-Organic Frameworks as Cancer Theranostic Agents

Metal-Organic Frameworks (MOFs) are hybrid multifunctional platforms that have found remarkable applications in cancer treatment and diagnostics. Independently, these materials can be employed in cancer treatment as intelligent drug carriers in chemotherapy, photothermal therapy, and photodynamic therapy; conversely, MOFs can further be used as diagnostic tools in fluorescence imaging, magnetic resonance imaging, computed tomography imaging, and photoacoustic imaging. One essential property of these materials is their great ability to fine-tune their composition toward a specific application by way of a judicious choice of the starting building materials (metal nodes and organic ligands). Moreover, many advancements were made concerning the preparation of these materials, including the ability to downsize the crystallites yielding nanoporous porphyrin MOFs (NMOFs) which are of great interest for clinical treatment and diagnostic theranostic tools. The usage of porphyrins as ligands allows a high degree of multifunctionality. Historically these molecules are well known for their reactive oxygen species formation and strong fluorescence characteristics, and both have proved helpful in cancer treatment and diagnostic tools. The anticipation that porphyrins in MOFs could prompt the resulting materials to multifunctional theranostic platforms is a reality nowadays with a series of remarkable and ground-breaking reports available in the literature. This is particularly remarkable in the last five years, when the scientific community witnessed rapid development in porphyrin MOFs theranostic agents through the development of imaging technologies and treatment strategies for cancer. This manuscript reviews the most relevant recent results and achievements in this particular area of interest in MOF chemistry and application.

Applications of zeolitic imidazolate framework-8 (ZIF-8) in bone tissue engineering: A review

Bone tissue is a highly vascularized and dynamic tissue that continues to remodel throughout the life cycle of a person. Only a few researches are done on usage of zeolitic imidazolate framework-8 (ZIF-8) in the bone tissue engineering area. Hence, this review is focused on the application of the ZIF-8 in bone tissue engineering. This work includes an explanation of metal-organic frameworks (MOFs) and ZIF-8 including synthesis methods as well as biocompatibility and biomedical applications of ZIF-8. In fact, a literature review is provided on previous applications of ZIF-8 in bone tissue engineering. Also, the investigations related to employing ZIF-8 in bone scaffolds and drug delivery systems for the bone tissues are discussed, and future perspectives are also emphasized.