Distinct Proteins in Protein Corona of Nanoparticles Represent a Promising Venue for Endogenous Targeting - Part II: In vitro and in vivo Kinetics Study.

INTRODUCTION: Nanoparticles (NPs), upon introduction to the biological systems, become wrapped by serum and cellular proteins constituting the protein corona (PC). This PC contributes largely to the NPs' interaction with the biological systems and their subsequent functions. On the one hand, PC can decrease the efficiency of targeting by directing the NPs to the reticuloendothelial system (RES) or by masking the active targeting moieties and decreasing their ability to bind to their target receptors. On the other hand, some components of PC have offered hopes for achieving endogenous targeting. METHODS: In this study, we aimed at the investigation of the role of the PC in determining the behavior of cRGDyk peptide-unconjugated and -conjugated NPs (uNPs and cNPs) exhibiting different physicochemical properties and their interaction with melanoma on in vitro and in vivo levels. Mathematical modeling has been utilized to understand the kinetics of the interaction of NPs with the tumor cells and different organs, respectively. RESULTS: Endocytosis and exocytosis were reported to occur simultaneously for the utilized NPs. The balance was largely dependent on the NPs' physicochemical properties and the role of the PC. In addition, distinct proteins present in the PC (illustrated in the results of the PC analysis in part I) have also determined the patterns of the NPs' distribution in different organs and tissues of the vascular system, the RES system and the target tumot tissue. Vitronectin (VN) was found to mediate higher accumulation in integrin receptor-expressing melanoma cells, while complement 3 protein (C3) and clusterin (CLU), as an opsonin and dysopsonin, respectively, regulated the balance between the RES uptake and blood circulation. DISCUSSION: PC, if properly modulated by tuning NPs' physicochemical properties, can serve as a potential venue for optimum utilization of NPs in cancer therapy.

Distinct Proteins in Protein Corona of Nanoparticles Represent a Promising Venue for Endogenous Targeting - Part I: In vitro Release and Intracellular Uptake Perspective.

INTRODUCTION: Protein corona (PC) deposition on nanoparticles (NPs) in biological systems contributes to a great extent to NPs' fates; their targeting potential, the interaction with different biological systems and the subsequent functions. PC - when properly tuned - can serve as a potential avenue for optimization of NPs' use in cancer therapy. METHODS: Poly-lactic co-glycolic acid (PLGA)-based NPs exhibiting different physicochemical properties were fabricated and characterized. The PC makeup of these NPs were qualitatively and quantitatively analyzed by Western blot and Bradford assay, respectively. The effect of PC on the release of NPs' cargos and the intracellular uptake into B16F10 melanoma cells has been studied. RESULTS: The composition of NPs (polymeric PLGA NPs vs lipid-polymer hybrid NPs) and the conjugation of an active targeting ligand (cRGDyk peptide) represented the major determinants of the PC makeup of NPs. The in vitro release of the loaded cargos from the NPs depended on the PC and the presence of serum proteins in the release medium. Higher cumulative release has been recorded in the presence of proteins in the case of peptide conjugated NPs, cNPs, while the unconjugated formulations, uNPs, showed an opposite pattern. NPs intracellular uptake studies revealed important roles of distinct serum and cellular proteins on the extent of NPs' accumulation in melanoma cells. For example, the abundance of vitronectin (VN) protein from serum has been positively related to the intracellular accumulation of the NPs. CONCLUSION: Careful engineering of nanocarriers can modulate the recruitment of some proteins suggesting a potential use for achieving endogenous targeting to overcome the current limitations of targeted delivery of chemotherapeutic agents.

Ortner's syndrome due to large bilharzial pulmonary artery aneurysm.

Ortner's syndrome (cardiovocal syndrome) is a rare cause of unilateral vocal cord paralysis that results from compression of the left recurrent laryngeal nerve by enlarged vascular structures. Most commonly, it is caused by an enlarged left atrium, but other rare causes include ascending aortic aneurysm or pulmonary artery aneurysm. Although very rarely encountered nowadays, bilharziasis is still one of the main causes of pulmonary artery aneurysm in endemic areas. Hereby, we report a case of Ortner's syndrome due to a large pulmonary artery aneurysm in a woman with history of bilharziasis.

Targeted photodynamic-induced singlet oxygen production by peptide-conjugated biodegradable nanoparticles for treatment of skin melanoma.

BACKGROUND: Photodynamic therapy (PDT) has been determined to be a promising treatment modality in the most resistant tumors such as malignant melanoma. However, the key cytotoxic agent of PDT, -singlet oxygen (1O2) - represents a high risk of photodynamic-associated side effects e.g. skin photosensitization. Recently, controllable photosensitization, where 1O2 is produced on demand, has received increasing attention. In our study, this could be achieved via loading the photosensitizer (PS) in nanoparticles (NPs) decorated with target-specific moieties characterized by 1O2 quenching abilities to specifically locate the PS in the targeted cells and assure that 1O2 is only produced where desired after cellular processing. METHODS: Polymeric and hybrid lipid-polymer NPs were formulated and assayed for their physicochemical properties. This was followed by conjugation with an active targeting ligand, cRGDyk, cyclic (Arginine-Glycine-Aspartic acid-D-Tyrosine-Lysine) peptide. Finally, photodynamic potential of the selected formulations was assayed by quantification of 1O2 production and in vitro cytotoxicity. RESULTS: Three formulations were selected and nominated to be formulations of choice (FOCs); FOC-1 (200 nm, polymeric), FOC-2 (130 nm, polymeric) and FOC-3 (200 nm, hybrid). Physicochemical properties, most importantly particle size and NPs' composition have shown to be the major determinants in targeted NPs' 1O2 production and PDT-mediated cytotoxicity of melanoma. CONCLUSION: Proper selection of formulations intended for PDT application and target-specific ligands could achieve dual targeting; enhanced accumulation of NPs and protection of 1O2 production elsewhere other than target cells.