PLGA-modified nanoparticles for the treatment of hypo-vascularized HPV-related cervical cancers.

A major challenge associated with delivery of active agents in the female reproductive tract (FRT) is the ability of agents to efficiently diffuse through the cervicovaginal mucosa (CVM) and reach the underlying sub-epithelial immune cell layer and vasculature. A variety of drug delivery vehicles have been employed to improve the delivery of agents across the CVM and offer the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract. Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, polymeric NPs represent a promising option that has shown improved distribution through the CVM. This work summarizes recent experimental studies that have evaluated NP transport in the FRT, and highlights research areas that more thoroughly and efficiently inform polymeric NP design, including mathematical modeling. The studies presented below further expand on this to investigate the application of NPs in treating cancers found within the FRT. Advanced stage cancer treatments are often invasive and painful—typically comprised of surgery, chemotherapy, and/or radiation treatment. In addition to the poor transport associated with intravaginal delivery, low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies. To address these transport challenges, NPs are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. In the work presented below, the effect of surface modification with stealth polyethylene–glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies on NP distribution and chemotherapeutic efficacy, which is defined in this work as the ability of NPs to impart drug cytotoxicity and potency, was evaluated with the use of 3D cell culture models representing hypo-vascularized cervical cancerous tissue

Evaluation of drug-loaded gold nanoparticle cytotoxicity as a function of tumor tissue heterogeneity.

The inherent heterogeneity of tumor tissue presents a major challenge to nanoparticle-medicated drug delivery. This heterogeneity spans from the molecular to the cellular (cell types) and to the tissue (vasculature, extra-cellular matrix) scales. Here we employ computational modeling to evaluate therapeutic response as a function of vascular-induced tumor tissue heterogeneity. Using data with three-layered gold nanoparticles loaded with cisplatin, nanotherapy is simulated with different levels of tissue heterogeneity, and the treatment response is measured in terms of tumor regression. The results show that tumor vascular density non-trivially influences the nanoparticle uptake and washout, and the associated tissue response. The drug strength affects the proportion of proliferating, hypoxic, and necrotic tissue fractions, which in turn dynamically affect and are affected by the vascular density. This study establishes a first step towards a more systematic methodology to assess the effect of vascular-induced tumor tissue heterogeneity on the response to nanotherapy

Developing pharmacokinetic models for nano drug delivery systems

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, 2021, Universidade de Lisboa, Faculdade de Farmácia.A área dos nanomedicamentos é interdisciplinar e complexa com fontes de literatura terciárias, sobre a forma de manuais, emergentes desde os 2010 e, ainda assim, os processos que sustentam a farmacocinética e a farmacodinâmica de nanomedicamentos ainda não estão totalmente caracterizados. O objetivo desta monografia é apresentar, para os indivíduos que podem ser relativamente novos na área de nanomedicamentos, as propriedades farmacocinéticas de nanopartículas, as abordagens na modelação farmacocinética, e demonstrar a aplicação destes princípios em exemplos tanto de investigação fundamental, quanto no desenvolvimento e otimização bio galénica de nanomedicamentos. Aqui são descritas as etapas farmacocinéticas de absorção, distribuição, metabolização e eliminação referentes a nanomedicamentos, com realce nos aspetos que distinguem estes processos daquilo que é observado quando se trata de medicamentos “convencionais”. É também fornecida uma discussão sobre conceitos essenciais necessários para discussão de modelação farmacocinética usados nas abordagens compartimentais, mecanísticas, e baseadas na fisiologia. Diversos assuntos tangentes como corrente interesse na área de oncologia, extrapolação interespécies em estudos pré-clínicos e aspetos regulamentares associados são também brevemente abordados. Esta monografia foi realizada com base nas publicações disponíveis nas bases de dados de PubMed e Science Direct até ao mês de setembro do ano 2021. Este trabalho não é único e assemelha-se as revisões de Moss D. M. e Siccardi M., de Glassman P. M. e Muzakantov V. R., ou de Yuan D. et al quanto a organização bem como aos conteúdos.(1–3) A farmacocinética que descreve os medicamentos “convencionais” baseados na distribuição de substâncias ativas começa apenas quando as etapas finais de libertação e degradação das nanopartículas já começam a ocorrer. A existência simultânea de entidades particuladas e moleculares complica a descrição, otimização, desenvolvimento e avaliação regulamentar de novas formulações de nanomedicamentos. Isto, juntamente com a falta de técnicas analíticas adequadas para a quantificação de nanopartículas em meios biológicos, torna os estudos de modelação farmacocinética de nanomedicamentos um desafio.Nanomedicines are a complex and highly interdisciplinary field with recently emerging Textbooks as tertiary literature sources since 2010s, and yet the processes that underpin the pharmacokinetics and pharmacodynamics of nano drug delivery systems are not fully characterized. The aim of this monograph is to introduce the pharmacokinetic dispositions, pharmacokinetic modelling approaches, and to demonstrate application of these principles in examples of both basic research and NDDS development to individuals who may be relatively new to the field of nanomedicine. In this monograph are described the pharmacokinetic steps of absorption, distribution, metabolization and elimination particular to nano drug delivery systems, primarily focusing aspects that distinguish NDDS from “conventional” drugs. A description of essential concepts necessary for discussions of PK modelling in compartmental, mechanistic, and physiology-based approaches are also provided. Various related topics including growing interest in cancer therapy, interspecies extrapolation in pre-clinical study settings, and reglementary affairs related to NDDSs are also briefly addressed. Writing of this monograph was conducted after browsing information available in the PubMed and Science Direct databases up to September 2021. This work is not unique and resembles the reviews by Moss D. M. and Siccardi M., Glassman P. M. and Muzakantov V. R., and Yuan D. et al, in their structure, subject and contents.(1–3) Pharmacokinetics that describes small molecule active substances, begin only when the final steps of nanoparticles fate of release and degradation had begun. Simultaneous existence of both particulate and molecular entities complicates the description, optimization, development, and regulatory assessment of new nano formulations. This together with the lack of appropriate analytical techniques for nanoparticle quantification in biologic media makes pharmacokinetic modelling studies of NDDSs challenging

Physiologically based pharmacokinetic modeling of PLGA nanoparticles with varied mPEG content

Biodistribution of nanoparticles is dependent on their physicochemical properties (such as size, surface charge, and surface hydrophilicity). Clear and systematic understanding of nanoparticle properties’ effects on their in vivo performance is of fundamental significance in nanoparticle design, development and optimization for medical applications, and toxicity evaluation. In the present study, a physiologically based pharmacokinetic model was utilized to interpret the effects of nanoparticle properties on previously published biodistribution data. Biodistribution data for five poly(lactic-co-glycolic) acid (PLGA) nanoparticle formulations prepared with varied content of monomethoxypoly (ethyleneglycol) (mPEG) (PLGA, PLGA-mPEG256, PLGA-mPEG153, PLGA-mPEG51, PLGA-mPEG34) were collected in mice after intravenous injection. A physiologically based pharmacokinetic model was developed and evaluated to simulate the mass-time profiles of nanoparticle distribution in tissues. In anticipation that the biodistribution of new nanoparticle formulations could be predicted from the physiologically based pharmacokinetic model, multivariate regression analysis was performed to build the relationship between nanoparticle properties (size, zeta potential, and number of PEG molecules per unit surface area) and biodistribution parameters. Based on these relationships, characterized physicochemical properties of PLGA-mPEG495 nanoparticles (a sixth formulation) were used to calculate (predict) biodistribution profiles. For all five initial formulations, the developed model adequately simulates the experimental data indicating that the model is suitable for description of PLGA-mPEG nanoparticle biodistribution. Further, the predicted biodistribution profiles of PLGA-mPEG495 were close to experimental data, reflecting properly developed property–biodistribution relationships

Characterizing Targeted Therapeutic Delivery and Cellular Dynamics using In Vitro Cancer Disease Models

Cancer is a significant health risk to people living in developed and developing countries, which continues to prove difficult to treat. Common treatment options of cancers include surgical removal, radiation, and chemotherapies, which are often used in combination to improve the likelihood of successful treatment. Such combinatory approaches towards treatment are often taken because each approach is not targeted enough to function perfectly on its own. Being able to delivery therapeutic loads in a more targeted manner to sites of cancer has the capability of improving therapeutic efficiency and improving patient responses. The development of improved therapeutic delivery vehicles and screening systems can help serve the goal of improved targeted therapeutic delivery. The use of microfluidic devices for the study of therapeutic delivery has become popular over the past few decades because of the many benefits that they offer. Specifically, microfluidic devices only require small volumes of therapeutics for testing, which is often ideal because of limited drug supply during screening. Additionally, the high degree of control over channel geometries, ease of fabrication and low cost make microfluidic therapeutic testing devices well suited for higher throughput screening when run together in parallel. The ability to generate shear flow within the microfluidic channels also offers a means of more closely mimicking vascular physiology and conditions that would be experienced during drug delivery in the human body. Lastly, the use of microfluidic in therapeutic testing enables micro-scale data on characteristics such as binding, uptake, cellular permeability and others to be easily collected due to the transparent nature of the devices and ability to facilitate cell cultures. As such, the focus of this dissertation is mainly based around the establishment of microfluidic systems capable of mimicking cancerous environments and testing of various therapeutic vehicles and delivery methods targeted for cancer. In brief, the dissertation demonstrates a few methods of establishing cancerous environments within microfluidic systems of increasing complexity, and how screening of various nanoparticle vehicles and therapeutics is performed.First, a single layer microfluidic device is developed to facilitate the growth of cancer monolayers for the screening of solid lipid nanoparticle drug delivery performance. The device is designed to assist in identifying an optimal ratio of antibody to polymer chains exposed on the surface of the nanoparticles. Improved targeting of nanoparticles to cancer cells is achieved by increasing target specific binding through addition of cancer antibody while reducing non-specific binding through addition of polymer chains on the nanoparticles surface. Conditions for optimal targeting specifically to cancer cells were identified for nanoparticles with 37% of their surface area occupied by polyethelyene glycol (PEG). The cancer cell targeting efficiency for the 37% coated nanoparticles was determined to be a maximum of 81% when a cancer specific antibody was used in conjunction on the nanoparticles surface.Next, to improve the physiological relevance of the microfluidic screening system, a bi-layer setup was fabricated. The nature of the bi-layer device is designed to facilitate the co-culture of cancer and endothelial cells (ECs) in different compartments while still permitting signaling and chemical interactions to occur between the two cell types. The presence of ECs in the device is designed to mimic a blood vessel, as therapeutic delivery within the body relies heavily on the circulatory system from drug transport. As such, understanding the mechanics of therapeutic delivery from mimicked vasculature to cancer is an important consideration. Conditions in the bi-layer system influencing therapeutic transport include endothelial permeability, therapeutic size, system flow rate, and treatment time. Improved therapeutic delivery was achieved using smaller molecules, slower system flow rates, and when the EC monolayer was highly permeabilized. Increased treatment times, resulted in less and less therapeutic transport from the mimicked vessel to the cancer environment as the EC monolayer regained confluency. It was shown that the bi-layer microfluidic system functions to screen therapeutic delivery to a mimicked cancer environment under more physiologically relevant conditions.The next progression with the system was to test nanoparticle delivery and transport from the mimicked vessel to the cancer environment. This was accomplished utilizing the same bi-layer microfluidic setup in conjunction with a range of nanoparticle shapes that were utilized to identify characteristics that facilitate the greatest degree of therapeutic delivery. Specifically, spherical, short rod and long rod/worm-like nanoparticles were tested for their ability to transport therapeutic loads to the cancer environment over the course of 5 day treatments. Optimal nanoparticle shapes for each flow rate varied based on treatment time. Overall, nanoparticle drug delivery should be varied based on the degree of EC permeability which changes with time as the cancer environment is treated.Lastly, to improve the physiological relevance of cancer environments being used, a method for establishing and growing tumor spheroids within the microfluidic devices in an expedited fashion was developed. The ability to perform therapeutic and nanoparticle carrier screening on tumor spheroids as opposed to cancer monolayers provides feedback on efficiency and performance which more closely mimics outcomes observed in animal and clinical testing. In addition, the ability to form tumor spheroids in an expedited manner allows the screening process to be completed in a shorter period of time and with fewer initial cells. The use of convective driven nutrient flow is utilized to achieve such expedited cancer growth in a microfluidic system which also has the potential to facilitate therapeutic screening. The system has been shown to function with adherent and non-adherent cell types where 1.5 to 4.5 times faster growth can be achieved. The ability to cut tumor culturing times from 1 week to 3 days and reducing required cell counts from thousands to tens of cells has the potential to save lives in clinical settings when using patient derived samples

A Physiologically-Based Pharmacokinetic Model for Targeting Calcitriol-Conjugated Quantum Dots to Inflammatory Breast Cancer Cells.

Quantum dots (QDs) conjugated with 1,25 dihydroxyvitamin D3 (calcitriol) and Mucin-1 (MUC-1) antibodies (SM3) have been found to target inflammatory breast cancer (IBC) tumors and reduce proliferation, migration, and differentiation of these tumors in mice. A physiologically-based pharmacokinetic model has been constructed and optimized to match experimental data for multiple QDs: control QDs, QDs conjugated with calcitriol, and QDs conjugated with both calcitriol and SM3 MUC1 antibodies. The model predicts continuous QD concentration for key tissues in mice distinguished by IBC stage (healthy, early-stage, and late-stage). Experimental and clinical efforts in QD treatment of IBC can be augmented by in silico simulations that predict the short-term and long-term behavior of QD treatment regimens

Improving practices in nanomedicine through near real-time pharmacokinetic analysis

More than a decade into the development of gold nanoparticles, with multiple clinical trials underway, ongoing pre-clinical research continues towards better understanding in vivo interactions. The goal is treatment optimization through improved best practices. In an effort to collect information for healthcare providers enabling informed decisions in a relevant time frame, instrumentation for real-time plasma concentration (multi-wavelength photoplethysmography) and protocols for rapid elemental analysis (energy dispersive X-Ray fluorescence) of biopsied tumor tissue have been developed in a murine model. An initial analysis, designed to demonstrate the robust nature and utility of the techniques, revealed that area under the bioavailability curve (AUC) alone does not currently inform tumor accumulation with a high degree of accuracy (R2=0.56), marginally better than injected dose (R2=0.46). This finding suggests that the control of additional experimental and physiological variables (chosen through modeling efforts) may yield more predictable tumor accumulation. Subject core temperature, blood pressure, and tumor perfusion are evaluated relative to particle uptake in a murine tumor model. New research efforts are also focused on adjuvant therapies that are employed to modify circulation parameters, including the AUC, of nanorods and gold nanoshells. Preliminary studies demonstrated a greater than 300% increase in average AUC using a reticuloendothelial blockade agent versus control groups. Given a better understanding of the relative importance of the physiological factors that influence rates of tumor accumulation, a set of experimental best practices is presented. This dissertation outlines the experimental protocols conducted, and discusses the real-world needs discovered and how these needs became specifications of developed protocols

Multichannel Imaging to Quantify Four Classes of Pharmacokinetic Distribution in Tumors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108598/1/jps24086.pd

Magnetic Drug Targeting: Developing the Basics

Focusing medicine to disease locations is a needed ability to treat a variety of pathologies. During chemotherapy, for example, typically less than 0.1% of the drugs are taken up by tumor cells, with the remaining 99.9% going into healthy tissue. Physicians often select the dosage by how much a patient can physically withstand rather than by how much is needed to kill all the tumor cells. The ability to actively position medicine, to physically direct and focus it to specific locations in the body, would allow better treatment of not only cancer but many other diseases. Magnetic drug targeting (MDT) harnesses therapeutics attached to magnetizable particles, directing them to disease locations using magnetic fields. Particles injected into the vasculature will circulate throughout the body as the applied magnetic field is used to attempt confinement at target locations. The goal is to use the reservoir of particles in the general circulation and target a specific location by pulling the nanoparticles using magnetic forces. This dissertation adds three main advancements to development of magnetic drug targeting. Chapter 2 develops a comprehensive ferrofluid transport model within any blood vessel and surrounding tissue under an applied magnetic field. Chapter 3 creates a ferrofluid mobility model to predict ferrofluid and drug concentrations within physiologically relevant tissue architectures established from human autopsy samples. Chapter 4 optimizes the applied magnetic fields within the particle mobility models to predict the best treatment scenarios for two classes of chemotherapies for treating future patients with hepatic metastatic breast cancer microtumors

Design of Nanoparticle-Based Carriers for Targeted Drug Delivery

Nanoparticles have shown promise as both drug delivery vehicles and direct antitumor systems, but they must be properly designed in order to maximize efficacy. Computational modeling is often used both to design new nanoparticles and to better understand existing ones. Modeled processes include the release of drugs at the tumor site and the physical interaction between the nanoparticle and cancer cells. In this paper, we provide an overview of three different targeted drug delivery methods (passive targeting, active targeting, and physical targeting) and compare methods of action, advantages, limitations, and the current stages of research. For the most commonly used nanoparticle carriers, fabrication methods are also reviewed. This is followed by a review of computational simulations and models on nanoparticle-based drug delivery