Molecular interactions between dimethoxycurcumin and Pamam dendrimer carriers

Development of 177Lu-Cetuximab-PAMAM dendrimeric nanosystem: a novel theranostic radioimmunoconjugate

PURPOSE

Epidermal growth factor receptors (EGFRs) are overexpressed in a wide range of tumors and are attractive candidates to target in targeted therapies. This study aimed to introduce a novel radiolabeled compound, 177Lu-cetuximab-PAMAM G4, for the treatment of EGFR-expressing tumors.

METHODS

In this study, the cetuximab mAb was bound to PAMAM G4 and labeled with 177Lu via DTPA-CHX chelator. The synthesized nanosystem was confirmed by different analyses such as DLS, FT-IR, TEM, and RT-LC. Cell viability of the radioimmunoconjugate was assessed over the EGFR-expressing cell line of SW480. The biodistribution of 177Lu-Cetuximab-PAMAMG4 was determined in different intervals after injection of the radiolabeled compound in normal and tumoral nude mice via scarification and SPECT images.

RESULTS

The average size of PAMAM G4 and PAMAM-Cetuximab-DTPA-CHX nanoparticles were 2 and 70 nm, respectively. 177Lu-Cetuximab-PAMAMG4 was prepared with radiochemical purity of more than 98%. The survival rates of SW480 cells at 24, 48, and 72 h post-treatment with177Lu-Cetuximab-PAMAMG4 (500 nM) were 18%, 15%, and 14%, respectively. The biodistribution studies showed a significant accumulation of 177Lu-Cetuximab-PAMAM in the EGFR-expressing tumor.

CONCLUSION

According to the results, this new agent can be considered as an efficient therapeutic complex for tumors expressing EGFR receptors.

A Promising Anticancer Agent Dimethoxycurcumin: Aspects of Pharmacokinetics, Efficacy, Mechanism, and Nanoformulation for Drug Delivery

Curcumin is a well-known anticancer natural product with various significant bioactivities that has been well documented, but its widespread use is mainly hindered by insufficient ADME properties such as poor solubility and low metabolic stability. Dimethoxycurcumin (DiMC) is a kind of lipophilic compound derived from curcumin that maintains its anticancer potency and has greatly improved systematic bioavailability. Therefore, DiMC is regarded as a promising plant-derived anticancer agent that deserves to be well developed. Herein, we concentrate on the published work by those from original research groups concerned with the pharmacokinetics, efficacy, and mechanism of DiMC involved in the treatment of various tumors, as well as the nanoformulations for effective drug delivery.

The Role of Branch Cell Symmetry and Other Critical Nanoscale Design Parameters in the Determination of Dendrimer Encapsulation Properties

This article reviews progress over the past three decades related to the role of dendrimer-based, branch cell symmetry in the development of advanced drug delivery systems, aqueous based compatibilizers/solubilizers/excipients and nano-metal cluster catalysts. Historically, it begins with early unreported work by the Tomalia Group (i.e., The Dow Chemical Co.) revealing that all known dendrimer family types may be divided into two major symmetry categories; namely: Category I: symmetrical branch cell dendrimers (e.g., Tomalia, Vögtle, Newkome-type dendrimers) possessing interior hollowness/porosity and Category II: asymmetrical branch cell dendrimers (e.g., Denkewalter-type) possessing no interior void space. These two branch cell symmetry features were shown to be pivotal in directing internal packing modes; thereby, differentiating key dendrimer properties such as densities, refractive indices and interior porosities. Furthermore, this discovery provided an explanation for unimolecular micelle encapsulation (UME) behavior observed exclusively for Category I, but not for Category II. This account surveys early experiments confirming the inextricable influence of dendrimer branch cell symmetry on interior packing properties, first examples of Category (I) based UME behavior, nuclear magnetic resonance (NMR) protocols for systematic encapsulation characterization, application of these principles to the solubilization of active approved drugs, engineering dendrimer critical nanoscale design parameters (CNDPs) for optimized properties and concluding with high optimism for the anticipated role of dendrimer-based solubilization principles in emerging new life science, drug delivery and nanomedical applications.

Dendrimers as efficient nanocarriers for the protection and delivery of bioactive phytochemicals

The genesis of dendrimers can be considered as a revolution in nano-scaled bioactive delivery systems. These structures possess a unique potential in encapsulating/entrapping bioactive ingredients due to their tree-like nature. Therefore, they could swiftly obtain a valuable statue in nutraceutical, pharmaceutical and medical sciences. Phytochemicals, as a large proportion of bioactives, have been studied and used by scholars in several fields of pharmacology, medical, food, and cosmetic for many years. But, the solubility, stability, and bioavailability issues have always been recognized as limiting factors in their application. Therefore, the main aim of this study is representing the use of dendrimers as novel nanocarriers for phytochemical bioactive compounds to deal with these problems. Hence, after a brief review of phytochemical ingredients, the text is commenced with a detailed explanation of dendrimers, including definitions, types, generations, synthesizing methods, and safety issues; then is continued with demonstration of their applications in encapsulation of phytochemical bioactive compounds and their active/passive delivery by dendrimers. Dendrimers provide a vast and appropriate surface to entrap the targeted phytochemical bioactive ingredients. Several parameters can affect the yield of nanoencapsulation by dendrimers, including their generation, type of end groups, surface charge, core structure, pH, and ambient factors. Another important issue of dendrimers is related to their toxicity. Cationic dendrimers, particularly PAMAM can be toxic to body cells through attaching to the cell membranes and disturbing their functions. However, a number of solutions have been suggested to decrease their toxicity.

Structural changes in lipid mesophases due to intercalation of dendritic polymer nanoparticles: Swollen lamellae, suppressed curvature, and augmented structural disorder

Understanding interactions between nanoparticles and model membranes is relevant to functional nano-composites and the fundamentals of nanotoxicity. In this study, the effect of polyamidoamine (PAMAM) dendrimers as model nanoparticles (NP) on the mesophase behaviour of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) has been investigated using high-pressure small-angle X-ray scattering (HP-SAXS). The pressure-temperature (p-T) diagrams for POPE mesophases in excess water were obtained in the absence and presence of G2 and G4 polyamidoamine (PAMAM) dendrimers (29 Å and 45 Å in diameter, respectively) at varying NP-lipid number ratio (ν = 0.0002-0.02) over the pressure range p = 1-3000 bar and temperature range T = 20-80 °C. The p-T phase diagram of POPE exhibited the L_β, L_α and H_II phases. Complete analysis of the phase diagrams, including the relative area pervaded by different phases, phase transition temperatures (T_t) and pressures (p_t), the lattice parameters (d-spacing), the pressure-dependence of d-spacing (Δd/Δp), and the structural ordering in the mesophase as gauged by the Scherrer coherence length (L) permitted insights into the size- and concentration-dependent interactions between the dendrimers and the model membrane system. The addition of dendrimers changed the phase transition pressure and temperature and resulted in the emergence of highly swollen lamellar phases, dubbed L_β-den and L_α-den. G4 PAMAM dendrimers at the highest concentration ν = 0.02 suppressed the formation of the H_II phase within the temperature range studied, whereas the addition of G2 PAMAM dendrimers at the same concentration promoted an extended mixed lamellar region in which L_α and L_β phases coexisted. STATEMENT OF SIGNIFICANCE: Using high pressure small angle X-ray scattering in the pressure range 1-3000 bar and temperature range 20-60 °C, we have studied interactions between PAMAM dendrimers (as model nanoparticles) and POPE lipid mesophases (as model membranes). We report the pressure-temperature phase diagrams for the dendrimer-lipid mesophases for the first time. We find that the dendrimers alter the phase transition temperatures (T_t) and pressures (p_t), the lattice parameters (d-spacing), and the structural order in the mesophase. We interpret these unprecedented results in terms of the fluidity of the lipid membranes and the interactions between the dendrimers and the membranes. Our findings are of fundamental relevance to the field of nanotoxicity and functional nanomaterials that integrate nanoparticles and organized lipid structures.

Interactions between PAMAM dendrimers and DOPC lipid multilayers: Membrane thinning and structural disorder

BACKGROUND

Understanding the structure of hybrid nanoparticle-lipid multilayers is of fundamental importance to their bioanalytical applications and nanotoxicity, where nanoparticle-membrane interactions play an important role. Poly(amidoamine) (PAMAM) dendrimers are branched polymeric nanoparticles with potential biomedical applications due to precise tunability of their physicochemical properties. Here, the effect of PAMAM dendrimers (2.9-4.5 nm) with either a hydrophilic amine (NH₂) or a hydrophobic C₁₂ chain surface termination on the 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) multilayers has been studied for the first time.

METHODS

DOPC multilayers were created by the liposome-rupture method via drop-casting dendrimer-liposome dispersions with the dendrimers added at different concentrations and at three different stages. The multilayer structure was evaluated via the analysis of the synchrotron X-ray reflectivity (XRR) curves, obtaining the bilayer d-spacing, the coherence length from the Scherrer (L_s) analysis of the Bragg peaks, and the paracrystalline disorder parameter (g).

RESULTS

Dendrimer addition led to lipid bilayer thinning and more disordered multilayer structures. Larger hydrophobic dendrimers caused greater structural disruption to the multilayers compared to the smaller dendrimers. The smallest, positively charged dendrimers at their highest concentration caused the most pronounced bilayer thinning. The dendrimer-liposome mixing method also affected the multilayer structure due to different dendrimer aggregation involved.

CONCLUSIONS

These results show the complexity of the effect of dendrimer physicochemical properties and the addition method of dendrimers on the structure of mixed dendrimer-DOPC multilayers.

GENERAL SIGNIFICANCE

These insights are useful for fundamental understanding of nanotoxicity and future biomedical application of nanocomposite multilayer materials in which nanoparticles are added for enhanced properties and functionality.

Curcuminoids: Implication for inflammation and oxidative stress in cardiovascular diseases

It has been extensively verified that inflammation and oxidative stress play important roles in the pathogenesis of cardiovascular diseases (CVDs). Curcuminoids, from the plant Curcuma longa, have three major active ingredients, which include curcumin (curcumin I), demethoxycurcumin, and bisdemethoxycurcumin. Curcuminoids have been used in traditional medicine for CVDs' management and other comorbidities for centuries. Numerous studies had delineated their anti-inflammatory, antioxidative, and other medicinally relevant properties. Animal experiments and clinical trials have also demonstrated that turmeric and curcuminoids can effectively reduce atherosclerosis, cardiac hypertrophy, hypertension, ischemia/reperfusion injury, and diabetic cardiovascular complications. In this review, we introduce and summarize curcuminoids' molecular and biological significance, while focusing on their mechanistic anti-inflammatory/antioxidative involvements in CVDs and preventive effects against CVDs, and, finally, discuss relevant clinical applications.

PAMAM dendrimer - cell membrane interactions

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.

Augmentation of therapeutic potential of curcumin using nanotechnology: current perspectives

Curcumin, an active principle of Curcuma longa, is extracted from the rhizome. Its therapeutic efficiency has been proved using various in vitro and in vivo models. Inflammatory, neoplastic and preneoplastic diseases are the major targets using curcumin as therapeutic agent. Feasible clinical formulations could not be obtained because of its lack of solubility, stability and higher degradation rate. Recently, many techniques have been evolved to improve the physicochemical properties of pharmacological compounds, thereby increasing their biological activity. Curcumin has been developed using various techniques, particularly micro and nanotechnology to improve its stability and bioavailability. This review focuses on the studies pertaining to the delivery of curcumin in the form of micro and nanosize formulations for the treatment of a variety of diseases.

Biological and pharmacological evaluation of dimethoxycurcumin: A metabolically stable curcumin analogue with a promising therapeutic potential

Dimethoxycurcumin (DiMC) is a synthetic analog of curcumin with superior inter-related pro-oxidant and anti-cancer activity, and metabolic stability. Numerous studies have shown that DiMC reserves the biologically beneficial features, including anti-inflammatory, anti-carcinogenic, and cytoprotective properties, almost to the same extent as curcumin exhibits. DiMC lacks the phenolic-OH groups as opposed to curcumin, dimethoxycurcumin, and bis-demethoxycurcumin that all vary in the number of methoxy groups per molecule, and has drawn the attentions of researchers who attempted to discover the structure-activity relationship (SAR) of curcumin. In this regard, tetrahydrocurcumin (THC), the reduced and biologically inert metabolite of curcumin, denotes the significance of the conjugated α,β diketone moiety for the curcumin activity. DiMC exerts unique molecular activities compared to curcumin, including induction of androgen receptor (AR) degradation and suppression of the transcription factor activator protein-1 (AP-1). The enhanced AR degradation on DiMC treatment suggests it as a novel anticancer agent against resistant tumors with androgenic etiology. Further, DiMC might be a potential treatment for acne vulgaris. DiMC induces epigenetic alteration more effectively than curcumin, although both showed no direct DNA hypomethylating activity. Given the metabolic stability, nanoparticulation of DiMC is more promising for in vivo effectiveness. However, studies in this regard are still in its infancy. In the current review, we portray the various molecular and biological functions of DiMC reported so far. Whenever possible, the efficiency is compared with curcumin and the reasons for DiMC being more metabolically stable are elaborated. We also provide future perspective investigations with respect to varying DiMC-nanoparticles.

Dendrimer nanoarchitectures for cancer diagnosis and anticancer drug delivery

Dendrimers are novel nanoarchitectures with unique properties including a globular 3D shape, a monodispersed unimicellar nature and a nanometric size range. The availability of multiple peripheral functional groups and tunable surface engineering enable the facile modification of the dendrimer surface with different therapeutic drugs, diagnostic agents and targeting ligands. Drug encapsulation, and solubilizing and passive targeting also equally contribute to the therapeutic use of dendrimers. In this review, we highlight recent advances in the delivery of anticancer drugs using dendrimers, as well as other biomedical and diagnostic applications. Taken together, the immense potential and utility of dendrimers are envisaged to have a significant positive impact on the growing arena of drug delivery and targeting.

Exploring the use of nanocarrier systems to deliver the magical molecule; Curcumin and its derivatives

Curcumin and its derivatives; curcuminoids have been proven as potential remedies in different diseases. However, their delivery carries several challenges owing to their poor aqueous solubility, photodegradation, chemical instability, poor bioavailability and rapid metabolism. This review explores and criticizes the numerous attempts that were adopted through the years to entrap/encapsulate this valuable drug in nanocarriers aiming to reach its most appropriate and successful delivery system.

Preparation, characterization, in vivo pharmacokinetics, and biodistribution of polymeric micellar dimethoxycurcumin for tumor targeting

Dimethoxycurcumin (DMC) is an analog of curcumin with superior efficacy in various disease models. Currently, drug delivery system research on DMC is very limited, and it has become a huge challenge to realize further developments and clinical applications. In the present study, a kind of amphiphilic block copolymer, N-t-butoxycarbonyl-phenylalanine terminated monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone), or mPEG-PCL-Phe(Boc), was prepared from monomethoxyl poly (ethylene glycol)-b-poly (ε-caprolactone) (mPEG-PCL) with its hydroxyl terminal chemically converted into N-t-butoxycarbonyl-phenylalanine (Boc-Phe). This copolymer was determined to have a fairly low critical micelle concentration (2.56×10⁻³ mg/mL) and passive targeting potential to tumor tissue, and thus was applied to develop a polymeric micellar formulation of DMC for the first time. The DMC-loaded micelles prepared by thin-film hydration method had typical shell–core structure, with an average particle size of 17.9±0.4 nm and a polydispersity index of 0.045±0.011. The drug loading capacity and entrapment efficiency were 9.94%±0.15% and 97.22%±0.18%, respectively, indicating a high-affinity interaction between DMC and the copolymer. At a concentration of 2 mg/mL, the reconstituted micelle solution could be maintained for at least 10 days at room temperature, and displayed a low initial burst release followed by a sustained release in vitro. Pharmacokinetic study in rats revealed that in vivo drug exposure of DMC was significantly increased and prolonged by intravenously administering DMC-loaded micelles when compared with the same dose of free DMC dissolved in dimethyl sulfoxide. Furthermore, in vivo distribution results from tumor-bearing nude mice demonstrated that this micellar formulation significantly changed the biodistribution profile of DMC and increased drug accumulation in tumors. Therefore, the polymeric micellar formulation of DMC, based on the amphiphilic block copolymer, mPEG-PCL-Phe(Boc), could provide a desirable method for delivering DMC, especially for applications in cancer therapy.

A series of codendrimers from polyamidoamine (PAMAM) and oligoethylene glycols (OEG) dendrons as drug carriers: the effect of OEG dendron decoration degree

To evaluate the effect of OEG dendron decoration degree and find a suitable carrier, a series of codendrimers are prepared and utilized to transport methotrexate.

Advances in combination therapies based on nanoparticles for efficacious cancer treatment: an analytical report

The main objective of nanomedicine research is the development of nanoparticles as drug delivery systems or drugs per se to tackle diseases as cancer, which are a leading cause of death with developed nations. Targeted treatments against solid tumors generally lead to dramatic regressions, but, unfortunately, the responses are often short-lived due to resistant cancer cells. In addition, one of the major challenges of combination drug therapy (called "cocktail") is the crucial optimization of different drug parameters. This issue can be solved using combination nanotherapy. Nanoparticles developed in oncology based on combination nanotherapy are either (a) those designed to combat multidrug resistance or (b) those used to circumvent resistance to clinical cancer drugs. This review provides an overview of the different nanoparticles currently used in clinical treatments in oncology. We analyze in detail the development of combinatorial nanoparticles including dendrimers for dual drug delivery via two strategic approaches: (a) use of chemotherapeutics and chemosensitizers to combat multidrug resistance and (b) use of multiple cytotoxic drugs. Finally, in this review, we discuss the challenges, clinical outlook, and perspectives of the nanoparticle-based combination therapy in cancer.

Nanotechnology-applied curcumin for different diseases therapy

Curcumin is a lipophilic molecule with an active ingredient in the herbal remedy and dietary spice turmeric. It is used by different folks for treatment of many diseases. Recent studies have discussed poor bioavailability of curcumin because of poor absorption, rapid metabolism, and rapid systemic elimination. Nanotechnology is an emerging field that is potentially changing the way we can treat diseases through drug delivery with curcumin. The recent investigations established several approaches to improve the bioavailability, to increase the plasma concentration, and to enhance the cellular permeability processes of curcumin. Several types of nanoparticles have been found to be suitable for the encapsulation or loading of curcumin to improve its therapeutic effects in different diseases. Nanoparticles such as liposomes, polymeric nanoparticles, micelles, nanogels, niosomes, cyclodextrins, dendrimers, silvers, and solid lipids are emerging as one of the useful alternatives that have been shown to deliver therapeutic concentrations of curcumin. This review shows that curcumin's therapeutic effects may increase to some extent in the presence of nanotechnology. The presented board of evidence focuses on the valuable special effects of curcumin on different diseases and candidates it for future clinical studies in the realm of these diseases.

Spectroscopic and molecular modeling studies of the interaction between morin and polyamidoamine dendrimer

Interactions between the polyamidoamine (PAMAM) dendrimer and drug molecules are of interest for their potential biomedical applications. The goal of this work is to examine the interaction of PAMAM-C12 25% dendrimer with morin. The ultraviolet-visible, fluorescence spectroscopic methods as well as molecular modeling were used to analyze drug-binding mode, binding constants and binding sites, etc. The experimental data showed that the binding constant of morin-PAMAM-C12 25% is about 10(5) L/mol. The interaction of morin with PAMAM-C12 25% is mainly driven by the hydrophobic, electrostatic, hydrogen bonds and van der Waals forces. There are mainly three classes of binding site of morin at the interface of PAMAM-C12 25%. These results provided some useful information for self-assembling and disassembling the PAMAM dendrimer as well as efficient drug delivery and therapeutic applications.

Encapsulation of curcumin within poly(amidoamine) dendrimers for delivery to cancer cells

Curcumin has anti-proliferative and pro-apototic properties against a variety of cancer cells in vitro. Unfortunately, the water-insolubility and instability leads to its low bioavailability in vivo tests. Here, we report a general approach to using poly(amidoamine) dendrimer with acetyl terminal groups to encapsulate curcumin(G₅-Ac/Cur) for drug delivery to cancer cells. The solubility, release kinetics, anticancer activity, and apoptotic-related protein expression (Bax and Bcl-2) were investigated in detail. Comparing with curcumin, the water-solubility value of G₅-Ac/Cur increased 200-fold, and the release of curcumin from the complexes was in a sustained manner. G₅-Ac/Cur showed higher anti-proliferative activity against A549 cell lines and had the better effect on the generation of intracellular reactive oxygen species, the mitochondrial membrane potential and cell apoptosis. Furthermore, the ratio of Bax/Bcl-2 was higher in samples treated with G₅-Ac/Cur. The results indicated that the G₅-Ac drug delivery system could improve the solubility and anti-cancer effect of curcumin.

Surface-immobilized PAMAM-dendrimers modified with cationic or anionic terminal functions: physicochemical surface properties and conformational changes after application of liquid interface stress

Functionalization of surfaces with highly branched dendrimer molecules has gained attractiveness for various applications because the number of functional groups exceeds those of surfaces functionalized with self-assembled monolayers. So far, little is known about the physicochemical properties of dendrimer functionalized surfaces, especially if the flexibility of dendrimer structure remains after covalent immobilization. Therefore, the purpose of this study was to covalently immobilize polyamidoamine (PAMAM) dendrimer molecules exhibiting terminal amine and carboxyl groups to silicon model surfaces and to explore their properties and structure at the solid-air and solid-liquid interface. Our results show that the surface free energy is higher for PAMAM coatings than for analogously terminated SAMs and also higher for carboxyl than amine functionalized coatings. Furthermore, several findings suggest that conformational freedom of the dendrimers was preserved after surface immobilization. Wet compared to dry PAMAMNH(2) surfaces show reduced hydrophilicity and increased contact angle hysteresis, whereas PAMAMCOOH surfaces become more hydrophilic and showed decreased hysteresis. Streaming current measurements showed an unexpected behavior for PAMAMCOOH surfaces in that they reveal a net positive surface charge over a wide pH range in spite of the carboxylated periphery. All of these results indicate a certain degree of masking, burrowing, back-folding and unfolding of functional groups upon environmental changes.

Preparation and In vitro / In vivo characterization of spray dried microsphere formulation encapsulating 4-chlorocurcumin

The objective of the present study was to prepare and characterize in vitro and in vivo performance of a sustained release microsphere formulation of 4-chlorocurcumin, a novel curcumin analogue. A spray dried technique with ethylcellulose as the polymer was used in the preparation of these microspheres. Microspheres were characterized for drug content, particle size and shape, in vitro drug release and the drug-polymer interaction. To assess in vivo performance, both pharmacokinetics and hepatoprotective activity were investigated. Results were compared with an equivalent i.v. solution. The microspheres of 4-chlorocurcumin with ethylcellulose were successfully prepared using a spray-dried technique. These microspheres were able to sustain the release of the drug both in vitro as well as in vivo. Microspheres offered better pharmacokinetic and hepatoprotective properties to the drug compared to its solution form.

Dendrimers for enhanced drug solubilization

Approximately 40% of newly developed drugs are rejected by the pharmaceutical industry and will never benefit a patient because of low water solubility. Another 17% of launched drugs exhibit suboptimal performance for the same reason. Given the growing impact and need for drug delivery, a thorough understanding of delivery technologies that enhance the bioavailability of drugs is important. The high level of control over the dendritic architecture (size, branching density, surface functionality) makes dendrimers ideal excipients for enhanced solubility of poorly water-soluble drugs. Many commercial small-molecule drugs with anticancer, anti-inflammatory and antimicrobial activity have been formulated successfully with dendrimers, such as poly(amidoamine) (PAMAM), poly(propylene imine) (PPI or DAB) and poly(etherhydroxylamine) (PEHAM). Some dendrimers themselves show pharmaceutical activity in these three areas, providing the opportunity for combination therapy in which the dendrimers serve as the drug carrier and simultaneously as an active part of the therapy.

Recent advances in nanooncology

Nanobiotechnology is playing an important role in advances in oncology and currently nanooncology is the most important chapter of nanomedicine. Nanobiotechnologies have refined molecular diagnostics and enabled early detection of tumors and discovery of biomarkers of cancer. Various nanoparticles are the basis of diagnostic assays for cancer as well as contrast materials for MRI. Nanobiotechnology is facilitating the discovery and development of drugs for cancer. Several nanobiotechnologies, mostly based on nanoparticles, have been described to facilitate drug delivery in cancer, which is important for optimizing the effect of drugs and reducing toxic side effects. Nanoparticles for targeted drug delivery in cancer enable combination of diagnostics and therapeutics and act as adjuncts to hyperthermia and photodynamic therapy. Several applications of nanobiotechnology in cancer surgery include use of nanoparticles to visualize tumor during surgery as aid to proper removal, and nanorobotics for remotely controlled diagnostics combined with therapeutics. Selected new developments in nanooncology have been highlighted in this review and these point to an important role in development of personalized oncology.