Overview of mechanism and consequences of endothelial leakiness caused by metal and polymeric nanoparticles

Comparison of accumulation and distribution of PEGylated and CD-47-functionalized magnetic nanoporous silica nanoparticles in an in vivo mouse model of implant infection

INTRODUCTION

Drug targeting using nanoparticles is a much-researched topic. Rapid interactions of nanoparticles with the host's immune system and clearance from the circulation is a major problem resulting in non-satisfying accumulation rates in the desired region. The aim of the presented study was to compare organ distribution and implant accumulation of magnetic nanoporous silica nanoparticles (MNPSNP) functionalized with either Polyethylenglycol (PEG) or CD-47 in vivo in a mouse model of implant infection.

METHODS

Synthesis and functionalization of the magnetic core-shell nanoparticles is described. In the in vivo study, 32 mice were included and received an in staphylococcus aureus solution preincubated magnetic implant subcutaneously on the left and a nonmagnetic implant on the right hind leg. MNPSNP accumulation in the inner organs as well as on and around the implants was analyzed in dependence on the functionalization.

RESULTS

MNPSNP were successfully functionalized with PEG or CD-47. In vivo, unexpectedly both nanoparticle variants accumulated mainly in liver and spleen. In the tissue, surrounding the implants higher nanoparticle accumulation was seen in areas with more severe signs of inflammation Nanoparticles were detectable on both implant materials, but accumulation rate was very low.

CONCLUSION

Although various literature describes higher accumulation rates for nanoparticles functionalized with CD-47 in target areas and a reduced accumulation in liver and spleen, this could not be shown within this study. Possible instability or rapid agglomeration of the particles are conceivable reasons. Higher accumulation rates in areas with more severe signs of inflammation indicate that inflammatory cells might be essential for the delivery of nanoparticles into inflamed regions.

Gelatin nanocarriers in oncology: A biocompatible strategy for targeted drug delivery

Cancer persists as a formidable global health crisis, with conventional therapies often compromised by systemic toxicity, poor tumor specificity, and therapeutic resistance. Nanotechnology has emerged as a transformative approach, leveraging nanoscale materials to enhance drug bioavailability, enable targeted delivery, and mitigate off-target effects. Among these innovations, gelatin-based nanoparticles (GNPs), derived from collagen and endorsed by the FDA have garnered significant attention as biocompatible, biodegradable nanocarriers uniquely suited for oncology applications. GNPs address critical extracellular barriers such as inefficient tumor penetration, rapid clearance, and nonspecific biodistribution by capitalizing on gelatin's intrinsic advantages: low immunogenicity, tumor microenvironment responsiveness (pH, enzymes, redox gradients), and tunable surface functionalization. This review highlights the versatility of GNPs in overcoming these challenges through advanced strategies like ligand-mediated targeting, combinatorial therapies, and size-transformable systems that enhance tumor accumulation and therapeutic precision. Case studies across lung, breast, skin, liver, colorectal, brain, and head/neck cancers demonstrate GNPs' ability to reduce IC50 values by 2 to 4-fold, achieve >90 % apoptosis in malignant cells, and minimize damage to healthy tissues. Despite the challenges in translating gelatin-based nanocarriers from preclinical studies to clinical applications in cancer therapy, their promising preclinical performance highlights their potential as patient-centric platforms capable of advancing precision oncology. Further their adaptability, multifunctionality, and capacity for stimuli-responsive drug release underscore their potential to improve clinical outcomes, offering a targeted, low-toxicity paradigm for managing diverse malignancies.

Nanocarriers for targeted drug delivery in the vascular system: focus on endothelium

Endothelial cells (ECs) are pivotal in maintaining vascular health, regulating hemodynamics, and modulating inflammatory responses. Nanocarriers hold transformative potential for precise drug delivery within the vascular system, particularly targeting ECs for therapeutic purposes. However, the complex interactions between vascular ECs and nanocarriers present significant challenges for the development and clinical translation of nanotherapeutics. This review assesses recent advancements and key strategies in employing nanocarriers for drug delivery to vascular ECs. It suggested that through precise physicochemical design and surface modifications, nanocarriers can enhance targeting specificity and improve drug internalization efficiency in ECs. Additionally, we elaborated on the applications of nanocarriers specifically designed for targeting ECs in the treatment of cardiovascular diseases, cancer metastasis, and inflammatory disorders. Despite these advancements, safety concerns, the complexity of in vivo processes, and the challenge of achieving subcellular drug delivery remain significant obstacles to the effective targeting of ECs with nanocarriers. A comprehensive understanding of endothelial cell biology and its interaction with nanocarriers is crucial for realizing the full potential of targeted drug delivery systems.

Prospects for the Use of Metal-Based Nanoparticles as Adjuvants for Local Cancer Immunotherapy

Immunotherapy is among the most effective approaches for treating cancer. One of the key aspects for successful immunotherapy is to achieve a strong and stable antitumor immune response. Modern immune checkpoint therapy demonstrates that cancer can be defeated. However, it also points out the weaknesses of immunotherapy, as not all tumors respond to therapy and the co-administration of different immunomodulators may be severely limited due to their systemic toxicity. Nevertheless, there is an established way through which to increase the immunogenicity of immunotherapy-by the use of adjuvants. These enhance the immune response without inducing such severe adverse effects. One of the most well-known and studied adjuvant strategies to improve immunotherapy efficacy is the use of metal-based compounds, in more modern implementation-metal-based nanoparticles (MNPs), which are exogenous agents that act as danger signals. Adding innate immune activation to the main action of an immunomodulator makes it capable of eliciting a robust anti-cancer immune response. The use of an adjuvant has the peculiarity of a local administration of the drug, which positively affects its safety. In this review, we will consider the use of MNPs as low-toxicity adjuvants for cancer immunotherapy, which could provide an abscopal effect when administered locally.