Dictating the transport of drug carriers and augmenting the drug concentration at the desired anatomical site with high selectivity are worthwhile pursuits of current pharmaceutical research. Such ...approaches to drug targeting have been classified into passive and active strategies. As discussed in this article, active targeting promises greater selectivity because it exploits the incorporation of appropriate ligands, which are recognized by the target cells. Ligands, such as folate, peptides, transferrin, antibodies and their fragments, sugar, and sugar-mimetics, etc., with affinity to the molecules typical to or enriched in target tissues, have been investigated in this context. Mannose receptors (MRs) are abundantly expressed on a variety of cells, such as antigen-presenting cells, dendritic cells, and macrophages. Mannose receptors have lectin recognition domains that exhibit a high binding affinity for mannose. As a result, specific recognition of mannose-functionalized constructs has extensively been explored in the cell-specific targeting of drugs, vaccines, and other bioactive agents. This review outlines and discusses the key aspects of synthesis of mannosylated constructs, their mode of cellular uptake and application to targeted delivery of bioactive agents.
Hyaluronic acid (HA) is a high molecular weight, non-sulfated anionic polysaccharide from glycosamine glycan family. It is a versatile biomaterial that binds to specific cell receptor CD44 ...(frequently over-expressed on the tumor cell surface) and is useful in skin rejuvenation, drug delivery, tissue engineering and molecular imaging due to its biodegradable, non-toxic, biocompatible, non-immunogenic and non-inflammatory characteristics. It can be chemically modified by cross-linking, grafting, linking with hydrophobic substances and drugs, or through polyion complex formation with oppositely charged polysaccharides, proteins or surfactants. Its interpenetrating network produces self-assembled aggregates, nanoparticles and gels. The present review is aimed to provide recent updates on researches on HA, with an emphasis on different modification approaches. Various transformations in HA through covalent and non-covalent interactions and resulting applications in biomedical fields from the recent literature are described. Studies on stabilization of nanoparticles (NPs) and other colloidal carriers through layer-by-layer adsorption of HA are also highlighted. The article provides a greater visibility into the magnitude of HA application in the development of targeted drug vectors and implantable biomaterials.
•Updates on modification of hyaluronic acid (HA), forming self-assembled nano-aggregates of biomedical interest, are provided.•Crosslinked HA gels, conjugates, polyion complexes and interpenetration networks are discussed.•Adsorbed HA onto vesicular carriers and inorganic nanoparticles, providing a hydrophilic stealth, are described.
•Discussion on why the material perovskite is an ideal choice of researchers these days.•The details on progress in efficiency and stability within a decade.•Device architectures and fabrication ...techniques for laboratory and large scale purpose.•Factors responsible for rapid degradation in PSCs along with the issue of toxicity.•Commercialization status update.
Perovskite Solar Cells (PSCs) have grabbed the attention of the researchers worldwide owing to their outstanding Photovoltaic (PV) performance. PSCs are the future of the PV technology as they are capable of generating power with performance being comparable with the leading Silicon solar cells, with the cost being lower than Silicon solar cells. The enormous potential of PSCs is evident from the fact that the efficiency of these cells has risen from 3.8% to 25.2% within a decade, and it is continuously rising to date. We discuss the features making PSCs superior to contemporary PV technologies. The description of the evolution of efficiency and various architectures used to date has been presented. The perovskite film fabrication techniques with some large scale perovskite solar cell manufacturing techniques are discussed. Despite positive traits, the PSCs have faced some issues, such as degradation in the presence of moisture, oxygen, and UV, toxicity, etc. The impact of these factors with various remedies adopted by researchers has been discussed. However, the instability issue raised by toxicity is not of much concern is supported in this paper. These issues creating obstacles in the path of commercialization of PSCs along with the commercialization road map are discussed thoroughly.
Soft tissue reconstructs require materials that form three-dimensional (3-D) structures supportive to cell proliferation and regenerative processes. Polysaccharides, due to their hydrophilicity, ...biocompatibility, biodegradability, abundance, and presence of derivatizable functional groups, are distinctive scaffold materials. Superior mechanical properties, physiological signaling, and tunable tissue response have been achieved through chemical modification of polysaccharides. Moreover, an appropriate formulation strategy enables spatial placement of the scaffold to a targeted site. With the advent of newer technologies, these preparations can be tailor-made for responding to alterations in temperature, pH, or other physiological stimuli. In this review, we discuss the developmental and biological aspects of scaffolds prepared from four polysaccharides, viz. alginic acid (ALG), chitosan (CHI), hyaluronic acid (HA), and dextran (DEX). Clinical studies on these scaffolds are also discussed.
Abstract Colloidal nanocarriers, in their various forms, have the possibility of providing endless opportunities in the area of drug delivery. The current communication embodies an in-depth ...discussion of colloidal nanocarriers with respect to formulation aspects, types, and site-specific drug targeting using various forms of colloidal nanocarriers with special insights to the field of oncology. Specialized nanotechnological approaches like quantum dots, dendrimers, integrins, monoclonal antibodies, and so forth, which have been extensively researched for targeted delivery of therapeutic and diagnostic agents, are also discussed. Nanotechnological patents, issued by the U.S. Patent and Trademark Office in the area of drug delivery, are also included in this review to emphasize the importance of nanotechnology in the current research scenario. From the Clinical Editor Colloidal nanocarriers provide almost endless opportunities in the area of drug delivery. While the review mainly addresses potential oncological applications, similar approaches may be applicable in other conditions with a requirement for targeted drug delivery. Technologies including quantum dots, dendrimers, integrins, monoclonal antibodies are discussed, along with US-based patents related to these methods.
Liposomes have gained a lot of interest for drug delivery applications, and some of these preparations have been commercialized. These are formulated with biocompatible components and can be used for ...delivering a wide range of payloads differing in aqueous solubility and molecular weight. Liposome-based delivery approaches are limited mainly by two factors: (a) poor dispersion stability, and (b) pre-mature leakage of payloads. In this review, we have discussed the stabilization of liposomal vesicles by their entrapment in hydrogels. Studies reveal that such hydrogels can maintain the structural integrity of liposomes. Release of liposomes from the hydrogel network can be modulated through careful screening of matrix former and degree of its cross-linking. Accordingly, we have reviewed the approaches of stabilizing liposomal vesicles through entrapment in hydrogels. Application of liposome-embedded hydrogels has been reviewed in context of localized drug delivery. Our discussion is focussed on the delivery of bioactives to the skin. Such an approach appears alluring from the standpoint of minimizing the undesirable distribution of payload(s) the systemic circulation and off-target sites.
All-inorganic perovskite nanocrystals have emerged as an alternative for hybrid organic–inorganic perovskite for optoelectronic applications because of their unique optical, electrical properties and ...higher chemical stability. Doping of metal or metal nanoparticles into all-inorganic perovskite nanocrystals can modify or tune optical properties. In this paper, Ag-CsPbBr
3
nanocrystals were synthesized by the hot injection method. The influence of doped silver on the optical properties of CsPbBr
3
nanocrystals is analyzed by ultraviolet spectroscopy, PL spectroscopy, and Raman spectroscopy. There is an enhancement in the PL intensity and Raman intensity of Ag-CsPbBr
3
nanocrystals as compared to pristine CsPbBr
3
nanocrystals. The enhancement in the photoluminescence intensity and Raman intensity of Ag-CsPbBr
3
nanocrystals is due to localized surface plasmon resonance coupling between the doped silver and CsPbBr
3
nanocrystals. The photoluminescence intensity of Ag-CsPbBr
3
nanocrystals is quenched due to excessive doping concentration of silver and spectral self-absorption of the silver nanoparticle surface plasmon resonance. The silver ions play an important role in passivating surface defect states of CsPbBr
3
nanocrystals. The passivation of surface defect states improved the photoluminescence quantum yield and PL lifetime of the CsPbBr
3
nanocrystals. The study of Ag-CsPbBr
3
nanocrystals provides a new perspective for the future development of efficient and stable optoelectronic devices.
Optical design, photon management, and energy conversion efficiency are investigated through numerical simulation of perovskite/silicon tandem solar cell using the single-diode model. A strong ...near-infrared reflectance of roughly 60% is present in the perovskite-based top cell. ZnO and Si
3
N
4
anti-reflection coating layers are placed on the surface of the perovskite layer and silicon sub-cell of the tandem solar cell respectively for photon management and minimizing the near-infrared reflectance loss. ZnO will act as an electron transport layer as well as an anti-reflection coating layer. The ZnO layer will minimize the near-infrared reflectance loss by the top cell in the device structure and allow the maximum transmittance of near-infrared photon energy to the silicon sub-cell. Intermediate anti-reflection Si
3
N
4
layer assists in the maximum localization of the transmitted near-infrared photon energy in the silicon sub-cell. The efficiency of over 32% is achieved by optimizing the parameters of different materials such as perovskite, silicon, and anti-reflection coating layer in the tandem solar cell. The innovative idea of using electron transport material ZnO as an anti-reflection coating layer in the perovskite-based top cell can minimize the reflection loss by nearly 20%. The combination of ZnO and Si
3
N
4
anti-reflection coating layers improved the conversion efficiency of the tandem cell by 1%. This result paves the way to realize highly efficient tandem solar cells through photon management.
We present a fully reversible and highly efficient on-off photoswitching of magnetic resonance imaging (MRI) contrast with green (500 nm) and violet-blue (435 nm) light. The contrast change is based ...on intramolecular light-driven coordination-induced spin state switch (LD-CISSS), performed with azopyridine-substituted Ni-porphyrins. The relaxation time of the solvent protons in 3 mM solutions of the azoporphyrins in DMSO was switched between 3.5 and 1.7 s. The relaxivity of the contrast agent changes by a factor of 6.7. No fatigue or side reaction was observed, even after >100,000 switching cycles in air at room temperature. Electron-donating substituents at the pyridine improve the LD-CISSS in two ways: better photostationary states are achieved, and intramolecular binding is enhanced.
Persisting apical periodontitis is a primary reason for multiple intervention in root canal. Persisting bacteria in root canal is related with the persisting infection. Despite the advancement in ...treatment strategies the persisting infection is a major challenge for endodontist. Here we tested two newly developed quaternary ammonium methacrylates (QAMs) against endodontic bacteria and their biofilms. Their antibacterial and antibiofilm efficiency were compared with chlorhexidine (CHX) and sodium hypochlorite (NaOCl). We measured the MIC, MBC and MBIC of DMADDM and DMAHDM respectively. We also detected the ratio of live/dead bacteria and bacterial composition in the biofilms treated by DMADDM and DMAHDM. We found that DMADDM and DMAHDM could inhibit the growth of bacteria and biofilms formation. The result showed that novel QAMs were remarkably efficient than CHX against biofilms. In addition, we found that Streptococcus gordonii (S. gordonii) and Enterococcus faecalis (E. faecalis) were frequent isolates after treatment with antimicrobial compounds.
PDF
