Biodistribution Of Polymeric Nanoparticles Research Articles

Neonatal Pharmacokinetics and Biodistribution of Polymeric Nanoparticles and Effect of Surfactant.

The development of therapeutics for pediatric use has advanced in the last few decades, yet the off-label use of adult medications in pediatrics remains a significant clinical problem. Nano-based medicines are important drug delivery systems that can improve the bioavailability of a range of therapeutics. However, the use of nano-based medicines for application in pediatric populations is challenged by the lack of pharmacokinetic (PK) data in this population. To address this data gap, we investigated the PK of polymer-based nanoparticles in term-equivalent neonatal rats. We used poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticles, which are polymer nanoparticles that have been extensively studied in adult populations but less commonly applied in neonates and pediatrics. We quantified the PK parameters and biodistribution of PLGA-PEG nanoparticles in term-equivalent healthy rats and revealed the PK and biodistribution of polymeric nanoparticles in neonatal rats. We further explored the effects of surfactant used to stabilize PLGA-PEG particles on PK and biodistribution. We showed that 4 h post intraperitoneal injection, nanoparticles had the highest accumulation in serum, at 54.0% of the injected dose for particles with Pluronic® F127 (F127) as the stabilizer and at 54.6% of the injected dose for particles with Poloxamer 188 (P80) as the stabilizer. The half-life of the F127-formulated PLGA-PEG particles was 5.9 h, which was significantly longer than the 1.7 h half-life of P80-formulated PLGA-PEG particles. Among all organs, the liver had the highest nanoparticle accumulation. At 24 h after administration, the accumulation of F127-formulated PLGA-PEG particles was at 26.2% of the injected dose, and the accumulation of P80-formulated particles was at 24.1% of the injected dose. Less than 1% of the injected nanoparticles was observed in healthy rat brain for both F127- and P80-formulated particles. These PK data inform the use of polymer nanoparticle applications in the neonate and provide a foundation for the translation of polymer nanoparticles for drug delivery in pediatric populations.

Cationic Polymeric Nanoparticle Delivering CCR2 siRNA to Inflammatory Monocytes for Tumor Microenvironment Modification and Cancer Therapy.

Accumulating evidence has confirmed that malignant tumors have a complex microenvironment, which consists of a heterogeneous collection of tumor cells and other cell subsets (including the full gamut of immune cells). Tumor-associated macrophages (TAMs), derived from circulating Ly6Chi monocytes, constitute the most substantial fraction of tumor-infiltrating immune cells in nearly all cancer types and contribute to tumor progression, vascularization, metastasis, immunosuppression, and therapeutic resistance. Interrupting monocyte recruitment to tumor tissues by disturbing pivotal signaling pathways (such as CCL2-CCR2) is viewed as one of the most promising avenues for tumor microenvironment manipulation and cancer therapy. One critical issue for monocyte-based therapy is to deliver therapeutic agents into monocytes efficiently. In the present study, we systematically investigated the relationship between the surface potential and the biodistribution of polymeric nanoparticles in monocytes in vivo, aiming to screen and identify an appropriate delivery system for monocyte targeting, and we found that cationic nanoparticles have a higher propensity to accumulate in monocytes compared with their neutral counterparts. We further demonstrated that siCCR2-encapsulated cationic nanoparticle (CNP/siCCR2) could modify immunosuppressive tumor microenvironment more efficiently and exhibit superior antitumor effect in an orthotopic murine breast cancer model.

Simple and tunable surface coatings via polydopamine for modulating pharmacokinetics, cell uptake and biodistribution of polymeric nanoparticles

A strategy that can modulate biological response such as pharmacokinetics, cell uptake and biodistribution of NPs simply by tunable coatings was established.

Tumor targeting efficiency of bare nanoparticles does not mean the efficacy of loaded anticancer drugs: Importance of radionuclide imaging for optimization of highly selective tumor targeting polymeric nanoparticles with or without drug

The better understanding of polymeric nanoparticles as a drug delivery carrier is a decisive factor to get more efficient therapeutic response in vivo. Here, we report the non-invasive imaging of bare polymeric nanoparticles and drug-loaded polymeric nanoparticles to evaluate biodistribution in tumor bearing mice. To make nano-sized drug delivery carrier, glycol chitosan was modified with different degrees of hydrophobic N-acetyl histidine (NAcHis-GC-1, -2, and -3). The biodistribution of polymeric nanoparticles and drug was confirmed by using gamma camera with 131I-labeled NAcHis-GC and 131I-labeled doxorubicin (DOX) and by using in vivo live animal imaging with near-infrared fluorescence Cy5.5-labeled NAcHis-GC. Among bare nanoparticles, NAcHis-GC3 (7.8% NAcHis content) showed much higher tumor targeting efficiency than NAcHis-GC1 (3.3% NAcHis content) and NAcHis-GC2 (6.8% NAcHis content). In contrast, for drug-loaded nanoparticles, DOX-NAcHis-GC1 displayed two-fold higher tumor targeting property than DOX-NAcHis-GC3. These data imply that the biodistribution and tumor targeting efficiency between bare and drug-loaded nanoparticles may be greatly different. Therapeutic responses for NAcHis-GC nanoparticles after drug loading were also evaluated. In xenograft animal model, we could find out that DOX-NAcHis-GC1 with higher tumor targeting of DOX has more excellent therapeutic effect than DOX-NAcHis-GC3 and free DOX. These results mean that the hydrophobic core stability might be a critical factor for tumor targeting efficiency of nanoparticles. The present study indicates that by using molecular imaging, we can select more appropriate nanoparticles with the highest tumor targeting properties, leading to exerting more excellent therapeutic results in cancer therapy.

Effects of particle size and surface charge on cellular uptake and biodistribution of polymeric nanoparticles

To elucidate the effects of particle size and surface charge on cellular uptake and biodistribution of polymeric nanoparticles (NPs), rhodamine B (RhB) labeled carboxymethyl chitosan grafted NPs (RhB-CMCNP) and chitosan hydrochloride grafted NPs (RhB-CHNP) were developed as the model negatively and positively charged polymeric NPs, respectively. These NPs owned well defined particle sizes (150–500 nm) and Zeta potentials (−40 mV – +35 mV). FITC labeled protamine sulfate (FITC-PS) loaded RhB-CMCNP and camptothecin (CPT) loaded RhB-CHNP with high encapsulation efficiency were prepared. The fluorescence stability in plasma and towards I − was investigated, and the result indicated it was sufficient for qualitative and quantitative analysis. NPs with high surface charge and large particle size were phagocytized more efficiently by murine macrophage. Slight particle size and surface charge differences and different cell lines had significant implications in the cellular uptake of NPs, and various mechanisms were involved in the uptake process. In vivo biodistribution suggested that NPs with slight negative charges and particle size of 150 nm were tended to accumulate in tumor more efficiently. These results could serve as a guideline in the rational design of drug nanocarriers with maximized therapeutic efficacy and predictable in vivo properties, in which the control of particle size and surface charge was of significance.

Factors Affecting the Clearance and Biodistribution of Polymeric Nanoparticles

Nanoparticle (NP) drug delivery systems (5−250 nm) have the potential to improve current disease therapies because of their ability to overcome multiple biological barriers and releasing a therapeutic load in the optimal dosage range. Rapid clearance of circulating nanoparticles during systemic delivery is a critical issue for these systems and has made it necessary to understand the factors affecting particle biodistribution and blood circulation half-life. In this review, we discuss the factors which can influence nanoparticle blood residence time and organ specific accumulation. These factors include interactions with biological barriers and tunable nanoparticle parameters, such as composition, size, core properties, surface modifications (pegylation and surface charge), and finally, targeting ligand functionalization. All these factors have been shown to substantially affect the biodistribution and blood circulation half-life of circulating nanoparticles by reducing the level of nonspecific uptake, delaying opsonization, and increasing the extent of tissue specific accumulation.