Description

In addition to precisely integrating molecular building pieces into extensible structures with regular pores and periodic frameworks, Crystalline Porous Materials (CPMs) also offer constrained molecular spaces for the interactions of electrons, photons and guest molecules. Certain luminous qualities can be obtained by integrating Aggregation-Induced Emission (AIE)- based units into crystalline porous frameworks. Because of their excellent photo-stability, high luminescence efficiency and extensively adjustable composition, AIE-based CPMs are valuable in biological applications such as biosensing, bioimaging and imaging-guided therapy. This concentrated on the manipulation of luminous properties and structure design of AIE-based CPMs, with particular emphasis on their applications in the biomedical domain. There was also discussion of the potential and difficulties in developing AIE-based CPMs for use in biomedical and chemical applications.

Metal nanoparticles

In the field of biomedical research, both bare and labeled metal Nanoparticles (NPs) have become invaluable tools in Surface-Enhanced Raman scattering (SERS) sensing applications. Label-free NPs, in particular, play a crucial role in investigating bacterial metabolism and classifying strains. Moreover, they enable the detection of diverse biomolecules at various cellular locations, facilitating successful SERS imaging within and on cells. A notable breakthrough involves the utilization of NPs labeled with reporter molecules to visualize spatial pH distribution within cells. However, the use of bare metal nanoparticles may sometimes lead to drawbacks, such as altering marker bands for the spin and oxidation states of hemeproteins. Conversely, bare non-metal substrates offer the advantage of high reproducibility through the Charge Transfer (CT) mechanism. Employing NPs labeled with achiral molecules allows discrimination of chiral molecules via the CT mechanism. Furthermore, SERS immunoassays have achieved spectral multiplexing and the detection of cancer biomarkers. This success is attributed to the Electromagnetic (EM) mechanism facilitated by NP aggregation, with or without antibodies, labeled with dyes undergoing specific reactions. These advancements underscore the versatility and promise of NPbased SERS techniques in biomedical research, providing valuable insights into cellular processes, biomolecular interactions and disease diagnostics. The utilization of thermal spray processes and coatings in biomedical contexts represents a recent and innovative development. Specifically, metallic coatings, notably titanium and its alloys, are applied onto metal prostheses through vacuum processes to yield nonoxidized titanium coatings. These coatings serve as bioinert surfaces, characterized by adequate roughness and porosity, facilitating mechanical interlocking with bone tissue. Moreover, bioactive coatings such as Hydroxyapatite (HAp) or fluorapatite, featuring bone-like phosphate structures, exhibit enhanced compatibility and performance. These materials promote the growth of bone tissue directly on the surface of the prosthesis, enhancing its integration and functionality within the body.

Biomedical applications

In recent years, the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in biomedical applications has seen a substantial rise, extending beyond total elemental analysis to include speciation studies. Particularly noteworthy is the emergence of single cell ICP-MS (SC-ICP-MS), a technique that allows the analysis of elemental species within individual cells, thereby adding a new dimension to this methodology. Crucial efforts have been directed towards enhancing the introduction of cell suspensions into the ICP, achieved through the development of nebulizer/spray chamber systems that optimize transport efficiencies, or low-volume laser ablation chambers. These advancements have been complemented by the introduction of commercial ICP-MS instruments designed to better control spectral interferences and time-of-flight instruments boasting improved sensitivity. Presents an overview of the significant possibilities explored by various authors for conducting single cell analysis using ICP-MS. It also revisits the most relevant biomedical applications, focusing on the analysis of individual cells in three distinct areas: Monitoring essential elements, studying the incorporation of metallodrugs and nanostructures and analyzing biomolecules through labeling procedures. Special attention is given to the description of proposed sample introduction systems and their analytical characteristics. The development of luminescent materials holds considerable significance across various fields including optical devices, chemical sensing, bio-imaging and disease therapeutics. The luminescent behavior of individual molecules primarily relies on their chromophore groups. Despite exhibiting strong emission in diluted solutions, most conventional luminophores experience diminished luminescent efficiency when aggregated or in solid states, thereby limiting their practical applications. Aggregation of luminescent molecules can lead to partial or complete fluorescence quenching, a phenomenon known as Aggregation-Caused Quenching (ACQ). This quenching is often attributed to the stacking of planar π-systems within luminophores. In the transition from free fluorescent molecules to aggregated state materials, luminescent properties are not solely dictated by the fluorophores present, but are significantly influenced by specific geometric arrangements, including linkage, orientation, alignment and configuration of molecular building units. In contrast to the traditional ACQ effect, Aggregation-Induced Emission (AIE) offers an alternative approach. AIE allows for enhanced luminescence upon aggregation, presenting opportunities for overcoming the limitations posed by ACQ. This phenomenon opens up avenues for the development of luminescent materials with improved performance and expanded applications.