Hybrid materials, or hybrids incorporating both organic and inorganic constituents, are emerging as a very potent and promising class of materials due to the diverse, but complementary nature of the properties inherent of these different classes of materials. The complementarity leads to a perfect synergy of properties of desired material and eventually an end-product. The diversity of resultant properties and materials used in the construction of hybrids, leads to a very broad range of application areas generated by engaging very different research communities. We provide here a general classification of hybrid materials, wherein organics– in -inorganics (inorganic materials modified by organic moieties) are distinguished from inorganics– in –organics (organic materials or matrices modified by inorganic constituents). In the former area, the surface functionalization of colloids is distinguished as a stand-alone sub-area. The latter area—functionalization of organic materials by inorganic additives—is the focus of the current review. Inorganic constituents, often in the form of small particles or structures, are made of minerals, clays, semiconductors, metals, carbons, and ceramics. They are shown to be incorporated into organic matrices, which can be distinguished as two classes: chemical and biological. Chemical organic matrices include coatings, vehicles and capsules assembled into: hydrogels, layer-by-layer assembly, polymer brushes, block co-polymers and other assemblies. Biological organic matrices encompass bio-molecules (lipids, polysaccharides, proteins and enzymes, and nucleic acids) as well as higher level organisms: cells, bacteria, and microorganisms. In addition to providing details of the above classification and analysis of the composition of hybrids, we also highlight some antagonistic yin-&-yang properties of organic and inorganic materials, review applications and provide an outlook to emerging trends.

Lanthanide-doped luminescent nanoparticles are an appealing system for nanothermometry with biomedical applications due to their sensitivity, reliability and minimally invasive thermal sensing properties. Here, we propose four unique hybrid organic-inorganic materials prepared by combining β-NaGdF4 and PMOs (Periodic Mesoporous Organosilica) or mSiO2 (mesoporous silica). PMO/mSiO2 materials are excellent candidates for biological/biomedical applications as they show high biocompatibility with the human body. On the other hand, the β-NaGdF4 matrix is an excellent host for doping lanthanide ions, even at very low concentrations with yet very efficient luminescence properties. We propose a new type of Er 3+ -Yb 3+ upconversion luminescence nanothermometers operating both in the visible and near infrared regime. Both spectral ranges permit promising thermometry performance even in aqueous environment. It is additionally confirmed that these hybrid materials are non-toxic to cells, which makes them very promising candidates for real biomedical thermometry applications. In several of these materials the presence of additional voids leaves space for future theranostic or combined thermometry and drug delivery applications in the hybrid nanostructures.

The process of porous calcium carbonate (CaCO ) covering on electrospun poly(ε-caprolactone) (PCL) fibers is described in this study. Uniform CaCO coatings, composed of vaterite microparticles and its aggregates, were formed on PCL fibers by mineral precipitation from solution under ultrasonic treatment. The porous structure of CaCO in vaterite polymorphic form is useful for loading of various substances (drugs and nanoparticles), and this property makes vaterite an appropriate material for design of drug delivery systems. Such mineralization was implemented to attain therapeutic and/or biological activity of tissue engineering scaffolds based on electrospun PCL, by means of CaCO coatings. Various structures and polymorphs of CaCO coatings were obtained by variation of growth conditions (time of fiber incubation in work solution, ultrasonic treatment of this system). Coating homogeneity, CaCO polymorphic form, morphology, and CaCO mass can be controlled by number of successive stages of fibrous material treatment. Cytotoxicity tests showed that PCL fibers mineralized with CaCO did not release substances toxic for cells. SEM images of PCL/CaCO scaffolds cultured with cells demonstrate that scaffolds supported cell adhesion and spreading. The presented results show the new technique of controlled PCL scaffold mineralization with vaterite, and an opportunity of using PCL/CaCO as scaffolds for tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 94-103, 2017.

Superficial fungal infections are of serious concern worldwide due to their morbidity and increasing distribution across the globe in this era of growing antimicrobial resistance. Delivery of antifungals to target...