Targeted delivery combined with controlled drug release has a pivotal role in the future of personalized medicine. This review covers the principles, advantages, and drawbacks of passive and active targeting based on various polymer and magnetic iron oxide nanoparticle carriers with drug attached by both covalent and noncovalent pathways. Attention is devoted to the tailored conjugation of targeting ligands (e.g., enzymes, antibodies, peptides) to drug carrier systems. Similarly, the approaches toward controlled drug release are discussed. Various polymer–drug conjugates based, for example, on polyethylene glycol (PEG), N-(2-hydroxypropyl)methacrylamide (HPMA), polymeric micelles, and nanoparticle carriers are explored with respect to absorption, distribution, metabolism, and excretion (ADME scheme) of administrated drug. Design and structure of superparamagnetic iron oxide nanoparticles (SPION) and condensed magnetic clusters are classified according to the mechanism of noncovalent drug loading involving...

Targeted Drug Delivery with Polymers and Magnetic Nanoparticles: Covalent and Noncovalent Approaches, Release Control, and Clinical Studies.

Chemistries that Facilitate Nanotechnology Kim E. Sapsford,† W. Russ Algar, Lorenzo Berti, Kelly Boeneman Gemmill,‡ Brendan J. Casey,† Eunkeu Oh, Michael H. Stewart, and Igor L. Medintz*,‡ †Division of Biology, Department of Chemistry and Materials Science, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, United States ‡Center for Bio/Molecular Science and Engineering Code 6900 and Division of Optical Sciences Code 5611, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States College of Science, George Mason University, 4400 University Drive, Fairfax, Virginia 22030, United States Department of Biochemistry and Molecular Medicine, University of California, Davis, School of Medicine, Sacramento, California 95817, United States Sotera Defense Solutions, Crofton, Maryland 21114, United States

Functionalizing nanoparticles with biological molecules: developing chemistries that facilitate nanotechnology.

Polymer encapsulated organic nanoparticles have recently attracted increasing attention in the biomedical field because of their unique optical properties, easy fabrication and outstanding performance as imaging and therapeutic agents. Of particular importance is the polymer encapsulated nanoparticles containing conjugated polymers (CP) or fluorogens with aggregation induced emission (AIE) characteristics as the core, which have shown significant advantages in terms of tunable brightness, superb photo- and physical stability, good biocompatibility, potential biodegradability and facile surface functionalization. In this review, we summarize the latest advances in the development of polymer encapsulated CP and AIE fluorogen nanoparticles, including preparation methods, material design and matrix selection, nanoparticle fabrication and surface functionalization for fluorescence and photoacoustic imaging. We also discuss their specific applications in cell labeling, targeted in vitro and in vivo imaging, blood vessel imaging, cell tracing, inflammation monitoring and molecular imaging. We specially focus on strategies to fine-tune the nanoparticle property (e.g. size and fluorescence quantum yield) through precise engineering of the organic cores and careful selection of polymer matrices. The review also highlights the merits and limitations of these nanoparticles as well as strategies used to overcome the limitations. The challenges and perspectives for the future development of polymer encapsulated organic nanoparticles are also discussed.

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Polymer-encapsulated organic nanoparticles for fluorescence and photoacoustic imaging

1.1. Cancer and Early Detection
Cancer is the second most common cause of death in the United States, trailing only heart disease in incidence. Despite significant worldwide investment in research, cancer remains responsible for 1 in 4 deaths in developed countries.1 Globally, over 14 million cancer diagnoses were reported in 2012, a figure expected to increase to over 22 million cases per annum in the next two decades.2 Estimated to kill over 1/2 million U.S. citizens, and with over 1.6 million new cases predicted to be diagnosed this year,3 cancer continues to present a major, yet unmet challenge to healthcare both globally and in the United States.

Cancer emerges from our own tissues, complicating both detection and treatment methods due to the similarities between the diseased tissue and healthy tissue.4,5 Despite this fact, the mortality rate from cancer is often greatly reduced by early detection of the disease. For example, non-small-cell lung cancer is responsible for the most cancer related deaths worldwide, with patients in the advanced stages of the disease having only 5–15% and <2% 5-year survival rates for stage III and IV patients, respectively.6 In contrast, patients who start therapy in the early stages of the disease (stage I) have markedly improved survival rates, with an 80% overall 5-year survival rate.6 Consequently, early diagnosis is essential to improving cancer patient prognosis.

At present, clinical detection of cancer primarily relies on imaging techniques or the morphological analysis of cells that are suspected to be diseased (cytology) or tissues (histopathology). Imaging techniques applied to cancer detection, including X-ray, mammography, computed tomography (CT), magnetic resonance imaging (MRI), endoscopy, and ultrasound, have low sensitivity and are limited in their ability to differentiate between benign and malignant lesions.7,8 While cytology, such as testing for cervical cancer via a Pap smear or occult blood detection, may be used to distinguish between healthy and diseased cells or tissues, it is not effective at detecting cancer at early stages. Similarly, histopathology, which generally relies on taking a biopsy of a suspected tumor, is typically used to probe the malignancy of tissues that are identified through alternative imaging techniques, such as CT or MRI, and may not be used alone to detect cancer in its early stages. As such, the development of assays and methods for early detection of cancer, before the disease becomes symptomatic, presents a major challenge.

Recent research within the field of nanotechnology has focused on addressing the limitations of the currently available methods for cancer diagnosis. Certain nanoparticle probes possess several unique properties that are advantageous for use in the detection of cancer at the early stages. In this review, we will discuss the advances in the development of nanoparticle-based methods for the detection of cancer by fluorescence spectroscopy. We will divide this topic into three categories: techniques that are designed for (1) the detection of extracellular cancer biomarkers, (2) the detection of cancer cells, and (3) the detection of cancerous tissues in vivo. We will discuss these strategies within the context of the nanoparticle probe used as well as the recognition moieties applied in each approach. Ultimately, the translation of these methods from the laboratory to the clinic may enable earlier detection of cancer and could extend patient survival through the ability to administer therapeutic treatment in the early stages of the disease.

While this review provides a comprehensive overview of the nanoparticle probes that are used to detect cancer in vitro and in vivo through fluorescence, there are several other relevant reviews that may be of interest to our readers, who may refer to the references for more generalized reviews of nanomaterials used for diagnostics and therapy,9–12 or more detailed insight into the specific types of nanoparticle probes (i.e., quantum dots,13 gold nanoparticles,14,15 upconversion nanoparticles,16 polymer dots,17,18 silica nanoparticles,19 polymeric nanoparticles, 20 etc.) for cancer diagnosis.

Nanoparticle Probes for the Detection of Cancer Biomarkers, Cells, and Tissues by Fluorescence

The focus of this review is to provide an overview of the chitosan based nanoparticles for various non-parenteral applications and also to put a spotlight on current research including sustained release and mucoadhesive chitosan dosage forms. Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary use and approved for wound dressing applications. Chitosan has been used as a carrier in polymeric nanoparticles for drug delivery through various routes of administration. Chitosan has chemical functional groups that can be modified to achieve specific goals, making it a polymer with a tremendous range of potential applications. Nanoparticles (NP) prepared with chitosan and chitosan derivatives typically possess a positive surface charge and mucoadhesive properties such that can adhere to mucus membranes and release the drug payload in a sustained release manner. Chitosan-based NP have various applications in non-parenteral drug delivery for the treatment of cancer, gastrointestinal diseases, pulmonary diseases, drug delivery to the brain and ocular infections which will be exemplified in this review. Chitosan shows low toxicity both in vitro and some in vivo models. This review explores recent research on chitosan based NP for non-parenteral drug delivery, chitosan properties, modification, toxicity, pharmacokinetics and preclinical studies.

https://www.mdpi.com/1999-4923/9/4/53/pdf

An Overview of Chitosan Nanoparticles and Its Application in Non-Parenteral Drug Delivery

Chitosan nanoparticles are good drug carriers because of their good biocompatibility and biodegradability, and can be readily modified. As a new drug delivery system, they have attracted increasing attention for their wide applications in, for example, loading protein drugs, gene drugs, and anticancer chemical drugs, and via various routes of administration including oral, nasal, intravenous, and ocular. This paper reviews published research on chitosan nanoparticles, including its preparation methods, characteristics, modification, in vivo metabolic processes, and applications.

https://www.dovepress.com/getfile.php?fileID=9661

Recent advances of chitosan nanoparticles as drug carriers.

Due to their small particle size and large and modifiable surface, nanoparticles have unique advantages compared with other drug carriers. As a research focus in recent years, polyethylene glycol-polylactic acid (PEG-PLA) block copolymer and its end-group derivative nanoparticles can enhance the drug loading of hydrophobic drugs, reduce the burst effect, avoid being engulfed by phagocytes, increase the circulation time of drugs in blood, and improve bioavailability. Additionally, due to their smaller particle size and modified surface, these nanoparticles can accumulate in inflammation or target locations to enhance drug efficacy and reduce toxicity. Recent advances in PEG-PLA block copolymer nanoparticles, including the synthesis of PEG-PLA and the preparation of PEG-PLA nanoparticles, were introduced in this study, in particular the drug release and modifiable characteristics of PEG-PLA nanoparticles and their application in pharmaceutical preparations.

/pdf/recent-advances-in-peg-pla-block-copolymer-nanoparticles-9do8ely974.pdf

Recent advances in PEG–PLA block copolymer nanoparticles

Poly(ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) block copolymers are biocompatible and amphiphilic polymers that can be widely utilized in the preparation of liposomes, polymeric nanoparticles, polymer hybrid nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, and microemulsions. Particularly, the terminal groups of PEG can be activated and linked to various targeting ligands, which can prolong the circulation time, improve the drug bioavailability, reduce undesirable side effects, and especially target specific cells, tissues, and even the intracellular localization in organelles. This review herein aims to describe recent developments in drug carriers exploiting PEG-DSPE block copolymers and their derivatives, and the incorporation of different ligands to the end groups of PEG-DSPE to target delivery, focusing on their modification approaches, advantages, applications, and the probable associated drawbacks.

/pdf/application-of-poly-ethylene-glycol-2gptw4gs73.pdf

Application of poly(ethylene glycol)–distearoylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery

The invention discloses folate-conjugated polyethylene glycol monostearate, and a preparation method and application thereof. The folate-conjugated polyethylene glycol monostearate has a structure shown as below, wherein n equals to 45-136. The preparation method of the folate-conjugated polyethylene glycol monostearate comprises the following steps: weighing folic acid and triethylamine; adding dimethylsulfoxide for dissolution; adding dicyclohexylcarbodiimide and N-hydroxy succinimide; stirring at room temperature by avoiding light; standing for overnight; filtering to remove by-products; then adding polyethylene glycol monostearate; heating to dissolve; reacting overnight to obtain a coarse product; placing the coarse product in a dialysis bag; dialyzing with water; and conducting freeze-drying to obtain the folate-conjugated polyethylene glycol monostearate. The folate-conjugated polyethylene glycol monostearate can be applied to preparation of a folic acid modified antitumor drug delivery system, improve drug targeting, efficacy and pharmacokinetics, and reduce toxicity.

Wang Junjie

Papers

Recent advances of chitosan nanoparticles as drug carriers.

Recent advances in PEG–PLA block copolymer nanoparticles

Application of poly(ethylene glycol)–distearoylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery

Folate-conjugated polyethylene glycol monostearate, and preparation method and application thereof

Oxaliplatin folic acid targeted lipidosome and application thereof