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Molecules (Basel, Switzerland) Apr 2018Dendrimers have come a long way in the last 25 years since their inception. Originally created as a wonder molecule of chemistry, dendrimer is now in the fourth class of... (Review)
Review
Dendrimers have come a long way in the last 25 years since their inception. Originally created as a wonder molecule of chemistry, dendrimer is now in the fourth class of polymers. Dr. Donald Tomalia first published his seminal work on Poly(amidoamine) (PAMAM) dendrimers in 1985. Application of dendrimers as a drug delivery system started in late 1990s. Dendrimers for drug delivery are employed using two approaches: (i) formulation and (ii) nanoconstruct. In the formulation approach, drugs are physically entrapped in a dendrimer using non-covalent interactions, whereas drugs are covalently coupled on dendrimers in the nanoconstruct approach. We have demonstrated the utility of PAMAM dendrimers for enhancing solubility, stability and oral bioavailability of various drugs. Drug entrapment and drug release from dendrimers can be controlled by modifying dendrimer surfaces and generations. PAMAM dendrimers are also shown to increase transdermal permeation and specific drug targeting. Dendrimer platforms can be engineered to attach targeting ligands and imaging molecules to create a nanodevice. Dendrimer nanotechnology, due to its multifunctional ability, has the potential to create next generation nanodevices.
Topics: Dendrimers; Drug Delivery Systems; Drug Liberation; Indomethacin; Resveratrol; Stilbenes
PubMed: 29670005
DOI: 10.3390/molecules23040938 -
Molecules (Basel, Switzerland) May 2016The main objective of this review is to describe the importance of dendrimer prodrugs in the design of new drugs, presenting numerous applications of these... (Review)
Review
The main objective of this review is to describe the importance of dendrimer prodrugs in the design of new drugs, presenting numerous applications of these nanocomposites in the pharmaceutical field. Therefore, the use of dendrimer prodrugs as carrier for drug delivery, to improve pharmacokinetic properties of prototype, to promote drug sustained-release, to increase selectivity and, consequently, to decrease toxicity, are just some examples of topics that have been extensively reported in the literature, especially in the last decade. The examples discussed here give a panel of the growing interest dendrimer prodrugs have been evoking in the scientific community.
Topics: Dendrimers; Drug Delivery Systems; Drug Design; Humans; Prodrugs
PubMed: 27258239
DOI: 10.3390/molecules21060686 -
Biomolecules Aug 2019Drug delivery systems are molecular platforms in which an active compound is packed into or loaded on a biocompatible nanoparticle. Such a solution improves the activity... (Review)
Review
Drug delivery systems are molecular platforms in which an active compound is packed into or loaded on a biocompatible nanoparticle. Such a solution improves the activity of the applied drug or decreases its side effects. Dendrimers are promising molecular platforms for drug delivery due to their unique properties. These macromolecules are known for their defined size, shape, and molecular weight, as well as their monodispersity, the presence of the void space, tailorable structure, internalization by cells, selectivity toward cells and intracellular components, protection of guest molecules, and controllable release of the cargo. Dendrimers were tested as carriers of various molecules and, simultaneously, their toxicity was examined using different cell lines. It was discovered that, in general, dendrimer cytotoxicity depended on the generation, the number of surface groups, and the nature of terminal moieties (anionic, neutral, or cationic). Higher cytotoxicity occurred for higher-generation dendrimers and for dendrimers with positive charges on the surface. In order to decrease the cytotoxicity of dendrimers, scientists started to introduce different chemical modifications on the periphery of the nanomolecule. Dendrimers grafted with polyethylene glycol (PEG), acetyl groups, carbohydrates, and other moieties did not affect cell viability, or did so only slightly, while still maintaining other advantageous properties. Dendrimers clearly have great potential for wide utilization as drug and gene carriers. Moreover, some dendrimers have biological properties per se, being anti-fungal, anti-bacterial, or toxic to cancer cells without affecting normal cells. Therefore, intrinsic cytotoxicity is a comprehensive problem and should be considered individually depending on the potential destination of the nanoparticle.
Topics: Animals; Cytotoxins; Dendrimers; Drug Carriers; Humans
PubMed: 31374911
DOI: 10.3390/biom9080330 -
International Journal of Pharmaceutics Jan 2020Dendrimers are globular structures, presenting an initiator core, repetitive layers starting radially from the core and terminal groups on the surface, resembling tree... (Review)
Review
Dendrimers are globular structures, presenting an initiator core, repetitive layers starting radially from the core and terminal groups on the surface, resembling tree architecture. These structures have been studied in many biological applications, as drug, DNA, RNA and proteins delivery, as well as imaging and radiocontrast agents. With reference to that, this review focused in providing examples of dendrimers used in nanomedicine. Although most studies emphasize cancer, there are others which reveal action in the neurosystem, reducing either neuroinflammation or protein aggregation. Dendrimers can carry bioactive compounds by covalent bond (dendrimer prodrug), or by ionic interaction or adsortion in the internal space of the nanostructure. Additionally, dendrimers can be associated with other polymers, as PEG (polyethylene glycol), and with targeting structures as aptamers, antibodies, folic acid and carbohydrates. Their products in preclinical/clinical trial and those in the market are also discussed, with a total of six derivatives in clinical trials and seven products available in the market.
Topics: Antineoplastic Agents; Chemistry, Pharmaceutical; Clinical Trials as Topic; Contrast Media; Dendrimers; Humans; Nanomedicine; Nanostructures; Neoplasms; Nervous System Diseases; Polyethylene Glycols; Prodrugs; Protein Aggregation, Pathological
PubMed: 31759101
DOI: 10.1016/j.ijpharm.2019.118814 -
Molecules (Basel, Switzerland) Sep 2020Biomedicine represents one of the main study areas for dendrimers, which have proven to be valuable both in diagnostics and therapy, due to their capacity for improving... (Review)
Review
Biomedicine represents one of the main study areas for dendrimers, which have proven to be valuable both in diagnostics and therapy, due to their capacity for improving solubility, absorption, bioavailability and targeted distribution. Molecular cytotoxicity constitutes a limiting characteristic, especially for cationic and higher-generation dendrimers. Antineoplastic research of dendrimers has been widely developed, and several types of poly(amidoamine) and poly(propylene imine) dendrimer complexes with doxorubicin, paclitaxel, imatinib, sunitinib, cisplatin, melphalan and methotrexate have shown an improvement in comparison with the drug molecule alone. The anti-inflammatory therapy focused on dendrimer complexes of ibuprofen, indomethacin, piroxicam, ketoprofen and diflunisal. In the context of the development of antibiotic-resistant bacterial strains, dendrimer complexes of fluoroquinolones, macrolides, beta-lactamines and aminoglycosides have shown promising effects. Regarding antiviral therapy, studies have been performed to develop dendrimer conjugates with tenofovir, maraviroc, zidovudine, oseltamivir and acyclovir, among others. Furthermore, cardiovascular therapy has strongly addressed dendrimers. Employed in imaging diagnostics, dendrimers reduce the dosage required to obtain images, thus improving the efficiency of radioisotopes. Dendrimers are macromolecular structures with multiple advantages that can suffer modifications depending on the chemical nature of the drug that has to be transported. The results obtained so far encourage the pursuit of new studies.
Topics: Animals; Anti-Inflammatory Agents; Biomedical Technology; Cell Death; Dendrimers; Diagnostic Imaging; Humans; Toxicity Tests
PubMed: 32882920
DOI: 10.3390/molecules25173982 -
Molecules (Basel, Switzerland) Sep 2018Polyamidoamine (PAMAM) dendrimers are one of the smallest and most precise nanomolecules available today, which have promising applications for the treatment of brain... (Review)
Review
Polyamidoamine (PAMAM) dendrimers are one of the smallest and most precise nanomolecules available today, which have promising applications for the treatment of brain diseases. Each aspect of the dendrimer (core, size or generation, size of cavities, and surface functional groups) can be precisely modulated to yield a variety of nanocarriers for delivery of drugs and genes to brain cells in vitro or in vivo. Two of the most important criteria to consider when using PAMAM dendrimers for neuroscience applications is their safety profile and their potential to be prepared in a reproducible manner. Based on these criteria, features of PAMAM dendrimers are described to help the neuroscience researcher to judiciously choose the right type of dendrimer and the appropriate method for loading the drug to form a safe and effective delivery system to the brain.
Topics: Animals; Blood-Brain Barrier; Brain Diseases; Dendrimers; Drug Carriers; Humans; Particle Size; Polyamines
PubMed: 30177605
DOI: 10.3390/molecules23092238 -
Molecules (Basel, Switzerland) Sep 2020Nanostructured hyperbranched macromolecules have been extensively studied at the chemical, physical and morphological levels. The cellular structural and functional... (Review)
Review
Nanostructured hyperbranched macromolecules have been extensively studied at the chemical, physical and morphological levels. The cellular structural and functional complexity of neural cells and their cross-talk have made it rather difficult to evaluate dendrimer effects in a mixed population of glial cells and neurons. Thus, we are at a relatively early stage of bench-to-bedside translation, and this is due mainly to the lack of data valuable for clinical investigations. It is only recently that techniques have become available that allow for analyses of biological processes inside the living cells, at the nanoscale, in real time. This review summarizes the essential properties of neural cells and dendrimers, and provides a cross-section of biological, pre-clinical and early clinical studies, where dendrimers were used as nanocarriers. It also highlights some examples of biological studies employing dendritic polyglycerol sulfates and their effects on glia and neurons. It is the aim of this review to encourage young scientists to advance mechanistic and technological approaches in dendrimer research so that these extremely versatile and attractive nanostructures gain even greater recognition in translational medicine.
Topics: Animals; Anti-Inflammatory Agents; Brain; Brain Neoplasms; Dendrimers; Humans; Neurons
PubMed: 33007959
DOI: 10.3390/molecules25194489 -
Biomolecular Concepts Jun 2015Recently, there have been tremendous advances in the development of various nanotechnology-based platforms for diagnosis and therapy. These nanoplatforms, which include... (Review)
Review
Recently, there have been tremendous advances in the development of various nanotechnology-based platforms for diagnosis and therapy. These nanoplatforms, which include liposomes, micelles, polymers, and dendrimers, comprise highly integrated nanoparticles that provide multiple functions, such as targeting, imaging, and therapy. This review focuses on dendrimer-based nanocarriers that have recently been developed for 'theranostics (or theragnosis)', a combination of therapy and diagnostics. We discuss the in vitro and in vivo applications of these nanocarriers in strategies against diseases including cancer. We also explore the use of dendrimers as imaging agents for fluorescence imaging, magnetic resonance imaging, X-ray computed tomography, and nuclear medical imaging.
Topics: Animals; Dendrimers; Humans; Magnetic Resonance Imaging; Neoplasms; Optical Imaging; Theranostic Nanomedicine; Tomography, X-Ray Computed
PubMed: 26136305
DOI: 10.1515/bmc-2015-0012 -
Advances in Colloid and Interface... Jul 2018PAMAM dendrimers have been conjectured for a wide range of biomedical applications due to their tuneable physicochemical properties. However, their application has been... (Review)
Review
PAMAM dendrimers have been conjectured for a wide range of biomedical applications due to their tuneable physicochemical properties. However, their application has been hindered by uncertainties in their cytotoxicity, which is influenced by dendrimer generation (i.e. size and surface group density), surface chemistry, and dosage, as well as cell specificity. In this review, biomedical applications of polyamidoamine (PAMAM) dendrimers and some related cytotoxicity studies are first outlined. Alongside these in vitro experiments, lipid membranes such as supported lipid bilayers (SLBs), liposomes, and Langmuir monolayers have been used as cell membrane models to study PAMAM dendrimer-membrane interactions. Related experimental and theoretical studies are summarized, and the physical insights from these studies are discussed to shed light on the fundamental understanding of PAMAM dendrimer-cell membrane interactions. We conclude with a summary of some questions that call for further investigations.
Topics: Animals; Cell Membrane; Cell Survival; Dendrimers; Drug Delivery Systems; Humans
PubMed: 30008347
DOI: 10.1016/j.cis.2018.06.005 -
Drug Delivery 2017Positron emission tomography (PET) imaging offers physiological and biological information through the in vivo distribution of PET agents for disease diagnosis, therapy... (Review)
Review
Positron emission tomography (PET) imaging offers physiological and biological information through the in vivo distribution of PET agents for disease diagnosis, therapy monitoring and prognosis evaluation. Due to the unique structural characteristics allowing for facile modification of targeting ligands and radionuclides, dendrimers can be served as a versatile scaffold to build up various PET imaging agents, and significant breakthroughs have been made in this field over the past decades. This review focuses on the recent advances in dendrimer-based contrast agents for PET imaging of cancer, cardiovascular and other diseases. In particular, radiolabeling strategies for different PET isotopes are described in detail. Several challenges involved in clinical translation of radiolabeled dendrimers are also discussed.
Topics: Animals; Cardiovascular Diseases; Contrast Media; Dendrimers; Humans; Neoplasms; Positron-Emission Tomography
PubMed: 29124984
DOI: 10.1080/10717544.2017.1399299