Metal and metal oxide nanoparticles have many promising applications in biomedicine and pharmacy. One of the applications that has been widely studied over the last decade is their use as anticancer drug carriers. This review fills a gap in the literature by concentrating exclusively on biosynthesized zinc oxide nanoparticles (ZnO NPs) for targeted anticancer drug delivery. ZnO NPs have been suggested as a feasible prospect, among other metal-based NPs, because of their unique properties and biocompatible nature. The use of ZnO NPs in drug delivery could reduce the dosage of drugs used for cancer treatment and reduce other side effects, by aiming the specific sites of cancer cells. Green methods of synthesis, with the use of natural products and living organisms, have become very popular in last decades due to their numerous advantages. They are not only eco-friendly and less expensive but they also allow to avoid the waste of energy and receive the NPs with well-defined size and morphology. The biosynthesized ZnO NPs have inherent advantages because they are made with the use of bioactive capping agents. Therefore, they show enhanced performance in drug delivery as they have improved stability, biocompatibility and targeting. This review includes a comparative analysis of synthesis methods and a comprehensive survey of their application as nanocarriers for various anticancer drugs. Their development faces several challenges related to synthesis, toxicity, scalability of the process, and limited understanding of the biochemical mechanisms involved in reduction and stabilization of metal ions through biological agents. Although biosynthesized ZnO NPs show a lot of potential as nanocarriers in laboratory conditions, their use in clinical trials is very challenging and requires collaboration between scientists, process engineers, clinicians and regulatory agencies. However, if these challenges are addressed and treated properly, their full commercial value and widespread applications will be enabled.
Rosavin, a bioactive compound derived from Rhodiola rosea, has been proposed to modulate osteoblast-associated signaling pathways. Emerging evidence highlights the role of CX3CL1 (fractalkine) in bone–immune interactions. This study aimed to investigate whether rosavin modulates CX3CL1 secretion and osteoblast morphology and confluence in human osteoblasts (HOB) in vitro, thereby providing descriptive cellular evidence relevant to CX3CL1-associated osteoblast responses under mineralizing conditions. Prior to biological testing, the chemical identity of rosavin was verified by high-resolution electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS). HOB were cultured in growth medium (DMEM-g), mineralization medium (DMEM-m), or DMEM-m supplemented with rosavin at 50 µM (R50) or 100 µM (R100). Cell morphology and confluence were assessed by phase-contrast microscopy, supported by semi-quantitative image-based estimation of cell-covered area using Fiji/ImageJ. Sirius Red staining was performed only in the DMEM-m mineralization control group and was evaluated qualitatively as a supportive assessment of extracellular matrix maturation. Rosavin was associated with dose- and time-dependent changes in CX3CL1 secretion and morphology-related observations in HOB cultures. The 50 µM rosavin condition showed significantly increased CX3CL1 secretion at days 14 and 21 compared with DMEM-m alone and was associated with higher cell confluence and predominance of cuboidal cell morphology. In contrast, the 100 µM condition was associated with lower apparent confluence, mixed cellular morphology, and reduced CX3CL1 secretion at later time points. These observations are descriptive, preliminary, and hypothesis-generating. Rosavin was associated with concentration-dependent modulation of CX3CL1 secretion and osteoblast morphological characteristics in vitro; however, the biological significance of CX3CL1 modulation in this monoculture model remains uncertain. Further mechanistic and functional studies are required.
The development of a universal SARS-CoV-2 vaccine holds great promise for achieving broad and durable protection against existing and future coronavirus variants. The identification, selection, and rational redesign of conserved viral epitopes constitute the direct immunological foundation of universal SARS-CoV-2 vaccine development. The breadth and durability of protection are therefore primarily determined at the level of antigen and epitope design, whereas adjuvants, delivery platforms, and routes of administration serve as enabling and amplifying components rather than primary drivers of universality. Accordingly, this review discusses key determinants of universal vaccine design, including antigen selection, adjuvant utilization, and route of administration. The spike protein, particularly its receptor-binding domain, is a major antigenic target, but its high mutation rate challenges long-term vaccine efficacy. Strategies focusing on conserved epitopes in antigen designs show potential to elicit cross-neutralizing immune responses. Nanoparticle-based vaccines capable of presenting multiple homologous or heterologous antigens have demonstrated enhanced immunogenicity, broad protection in preclinical models and safety in clinical trials. The addition of next-generation adjuvants further amplifies humoral and cellular immunity beyond the capabilities of traditional aluminum-based adjuvants. Moreover, mucosal vaccine delivery may provide superior local protection at viral entry sites and limit transmission. Importantly, integrating these technological advances with epitope-centered antigen design and immunological data from vaccinated individuals will accelerate the identification of conserved epitopes and inform future vaccine design. A multidisciplinary approach combining optimized antigen engineering, novel adjuvant systems, and innovative delivery strategies is essential for the realization of a broadly protective universal SARS-CoV-2 vaccine.
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This study presents a novel strategy for studying the microstructure of PLGA-PEG-PLGA triblock copolymers synthesized via the ROP mechanism using various organic catalysts. The use of model copolymers (PLG-PEG-PLG, PLA-PEG-PLA) and multidimensional NMR spectroscopy (HSQC, HMBC, DOSY) enabled a more comprehensive characterization of the structure of PLGA-PEG-PLGA copolymers. The new method was verified by comparing the average molecular weights with the reference method-gel permeation chromatography. NMR analysis demonstrated a close correlation between the type of catalyst used, the monomer sequence arrangement, and the average molecular weights. The Zn(acac)₂ and Fe(acac)₃ catalysts demonstrated similar activity to the commonly used Sn(Oct)₂, making them potential substitutes in the synthesis of PLGA-PEG-PLGA copolymers. The proposed methodology provides detailed insight into copolymer microstructure, enabling more precise design of copolymers, which is essential for optimizing drug delivery systems.
