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Waterborne polyurethane (WPU) and Ag NPs have been applied widely in packaging. However, WPU was susceptible to the contamination due to high moisture absorption, and the stability of Ag NPs in matrix polymers was still low. To resolve this problem, chitosan (CS) was used as the dispersant to synthesize CS/Ag NPs composites in this work, and then they were mixed with WPU to prepare CS/Ag-WPU films. CS macromolecules provided the carriers for Ag NPs with a diameter of about 2.5 nm, and Ag NPs were dispersed stably in WPU. Compared with pure WPU film, as-prepared CS/Ag-WPU films had a higher thermal stability at low temperature, and the crystal size for WPU increased after introducing CS/Ag NPs. Importantly, the water contact angle for CS/Ag-WPU-5 increased to 54.2° from 27.5° implying that the hydrophobicity was improved. In addition, CS/Ag-WPU composites exhibited an excellent inhibitory effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Antibacterial performances of most samples were improved with the crease of the concentration of CS, and the inhibitory effect on S. aureus was preferred. Therefore, as-prepared CS/Ag-WPU films in this paper have a potential application in antibacterial packaging field.

The present study focused on the green synthesis of silver nanoparticles from Coriander sativum (CS) containing structural polymers, phenolic compounds and glycosidic bioactive macromolecules. Plant phenolic compounds can act as antioxidants, lignin, and attractants like flavonoids and carotenoids. Henceforth, silver nanoparticles (AgNPs) were prepared extracellularly by the combinatorial action of stabilizing and reduction of the CS leaf extract. The biologically synthesized CS-AgNPs were studied by UV-spectroscopy, zeta potential determination, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis to characterize and confirm the formation of crystalline nanoparticles. The synthesized nanoparticles demonstrated strong antimicrobial activity against all microbial strains examined with varying degrees. The scavenging action on free radicals by CS-AgNPs showed strong antioxidant efficiency with superoxide and hydroxyl radicals at different concentrations as compared with standard ascorbic acid. The presence of in vitro anticancer effect was confirmed at different concentrations on the MCF-7 cell line as revealed with decrease in cell viability which was proportionately related to the concentration of CS-AgNPs illustrating the toxigenic nature of synthesized nanoparticles on cancerous cells.

The development of drug resistant strains of the pathogenic fungi despite the availability of large number of drugs demands the development of new and more potential drug molecules. Dendrimer based drug molecules are comparatively less researched upon and a recent advancement in this field. The present study is concerned with the preparation of macromolecular ligand and its complex using ethylenediamine and methylmethacrylate as starting material. The reaction goes via Michael addition reaction and synthesized dendritic units were used as ligands to obtain metal-ligand complexes. Obtained ligand and its complex were characterized in terms of different techniques such as FTIR, 1H NMR, ESI-MS, UV–Vis and Elemental analysis. Further, the ligand and its complex were used to determine antifungal activity against C. albicans ATCC 90028 by MICs and Disk diffusion assay. Comet assay and Molecular docking techniques were used to show toxicity effects and ligand–DNA interactions respectively. Ligand and its complex were obtained in very good yield with square planar geometry and having good antifungal potential against C. albicans. It was also found from Molecular docking and Comet assay, that the Copper complex interacts strongly with DNA and shows less toxicity than ligand. The compounds can serve as promising leads for the development of new antifungal agents. Keywords: Michael addition, MICs, Disk diffusion assay, Comet assay, Docking, Antifungal

In an attempt to elucidate the aggregation behaviour of bovine serum albumin and its modulation by salt ions, size-exclusion high-performance liquid chromatography was used and complemented by dynamic light scattering. The influence of the protein concentration, and type and concentration of inorganic salt on the aggregation of albumin in solution have been analyzed. Based on the observations herein reported an aggregation mechanism is proposed, according to which (i) some functional groups of albumin dissociate in solution forming macromolecular ions; (ii) the macromolecular ions bind with each other into large aggregates; and (iii) the salt ions establish chemical equilibria with the charges of opposing character present in the macromolecular ions’ backbone, promoting or preventing the aggregation. The present work shows that the aggregation behaviour of bovine serum albumin in solution and its modulation by salt ions can be explained by chemical concepts, with chemical equilibrium playing an essential role. This work is funded by national funds (OE), through FCT – Fundação para a Ciência e a Tecnologia, Portugal, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. published

The chapter presents critical review of the past, present trends in the field of modification of carbohydrate macromolecules specific to nonstarch polysaccharide carbohydrates. It covers all the techniques used in modification of carbohydrate macromolecules including surface modification and in-depth modification. The chapter is addressed to researchers to have an up-to-date information on the research works carried out in modification of carbohydrate macromolecules. The chapter characteristically abridges the important works and developments in the last 5-10 years, giving carefully chosen examples in form of tables, which makes it easy for the readers to understand the literature. On the basis of past and present work, future research guidelines in the area of modification of carbohydrate macromolecules can be discussed.

Biological macromolecules are naturally occurring large cellular components responsible for a wide array of functions necessary for the growth and survival of living organisms. They also possess various bioactivities such as antimicrobial, antioxidant, antitumor, antiviral, antiinflammatory, antiproliferative, and hypoglycemic activities. The growing interest in bioactive macromolecules as potential therapeutical drugs has driven scientists to further study the association between their chemical structures and corresponding functions/activities. This chapter aims to provide a short overview on the structural features influencing the bioactivities of several biological macromolecules, namely l -amino acid oxidases, lysostaphin and metallo-β-lactamase-like lactonase and chitosan. As observed in this chapter, establishing the structure–activity relationship (SAR) can often prove to be challenging for macromolecules given the complexity of the three-dimensional organization level of proteins and the branched chains of the carbohydrates. Nevertheless, certain structural features influencing the bioactivities of macromolecules have been identified and could help to accelerate their development and application in the biomedical field. Indeed, a comprehensive understanding of biomacromolecule SARs remains necessary as information inferred from these studies may be crucial to many aspects of drug discovery and development, whether it is for primary screening or lead optimization, as well as for the designing of synthetic derivatives with improved properties.

Surface-Enhanced Raman Scattering (SERS) using colloidal metal (Ag, Au) nanoparticles has been regarded as a powerful method for detecting organic pollutants at vestigial levels. Although less investi- gated, the controlled synthesis of binary nanostructures comprising two metals provides an alternative route to SERS platforms with tuned surface plasmon resonances. Here, we demonstrate that the use of dendrimers allows the formation of distinct combinations of Ag:Au nanostructures that are composed of smaller metal nanocrystals. Our research highlights the role of the dendrimer macromolecules as a multipurpose ligand in the generation of such hybrid nanostructure, including as a reducing agent, an effective long-term colloidal stabilizer and as a molecular glue for interconnecting the primary metal nanocrystals. Noteworthy, the dendrimer-based Ag:Au hybrid nanostructures are more SERS sensitive as compared to the corresponding colloidal blends or to the single-phase metals, as revealed by using molecular pesticides as analytes in spiked water samples. We suggest that the high SERS sensitivity of the hybrid nanostructures is due to interparticle plasmonic coupling occurring between the primary metal nanoparticle aggregates, whose arrangement is templated by the presence of the dendrimer macromolecules. published

The structure and properties of nanocomposites based on amorphous polyarylene ether ketones with different functional side groups (methyl, phthalide, phthalimidine) are investigated. Nanocomposites are prepared by in situ filling of the polymers; metalloalkoxysiloxanes, namely, tris-(methyldiethoxysiloxy)iron, tetrakis-(methyldiethoxysiloxy)zirconium and tetrakis-(methyldiethoxysiloxy)hafnium, were used as precursors for the filler phase. It is demonstrated that the chemical structure and polarity of the matrix macromolecule side groups are the key factors that determine the design of an in situ generated nanofiller (size, density, inhomogeneity or a continuous network structure). The in situ filling of polyarylene ether ketones does not impair their unique thermal properties and promotes an improvement in the tensile stress for the breaking of the nanocomposites that they are based on. The discussed approach for preparing nanocomposites based on thermo-stable polymers is promising for the creation of functional materials with tunable characteristics, such as dielectric properties and their resistance to atomic oxygen. Keywords: Polyarylene ether ketone, Metalloalkoxysiloxane, A sol-gel process, Nanocomposite, The structure, Properties

Linear ladder polysilsesquioxanes (LPSQ-R) bearing fluoroaryl groups [R: p-fluorophenyl (F), p-trifluoromethylphenyl (F3) or pentafluorophenyl (F5)] were used to modify polylactide (PLA). Vibrational spectroscopy analysis suggested specific, non-covalent interactions between C O of PLA and fluoroaryl groups of LPSQ-R while quantum-chemical modelling performed for representative models indicated that the pattern of possible preferred contacts differs for LPSQ-F3 in respect to LPSQ-F and LPSQ-F5 (H····F hydrogen bonding against n→π* attractive interactions). It may affect interface phenomena in PLA/LPSQ-R systems. Thermal characteristics of PLA/LPSQ-R depended on the type of R and LPSQ-R content. Dielectric relaxation spectroscopy (DRS) studies revealed one relaxation process present in PLA and related to the glass transition. However, for PLA/LPSQ-R blends two processes were identified: glass transition and normal–mode relaxation. The modification with fluorinated macromolecules increased hydrophobicity of amorphous PLA and improved its mechanical and gas barrier properties, which can be of importance for packaging applications.

The intracellular environment contains a high concentration of biomacromolecules that present steric barriers and ample surface area for weak chemical interactions. Consequently, these forces influence protein conformations and protein self-assembly, with an outcome that depends on the sum of the effects resulting from crowding. Linkers are disordered domains that lack tertiary structure, and this flexible nature would render them susceptible to compression or extension under crowded conditions, compared to the equilibrium conformation in a dilute buffer. The change in distance between the linked proteins can become essential where it attenuates protein activity. In this chapter, we first discuss the experimental findings in vitro and in the cell on how linkers and other relevant macromolecules are affected by crowding. We focus on the dependence on the linker's size, flexibility, and the intra- and intermolecular interactions. Although the experimental data on the systematic variation of proteins in a buffer and cells is limited, extrapolating the available insights allows us to propose a protocol on how to engineer the directionality of crowding effects in the linker. Finally, we describe a straightforward experimental protocol on the determination of crowding sensitivity in a buffer and cell.

Lignin is the most abundant renewable resource that contains conjugated aromatic structures in nature. It blocks irradiation from medium wave ultraviolet rays (range of 290–320 nm) and thus is a natural macromolecular ultraviolet (UV)-blocker. However, factors such as its poor absorbance in long wave ultraviolet wavelength range (320–400 nm), which causes cumulative damages, its deep color, and poor compatibility have seriously hindered the applications of lignin in skincare products and as UV-blocking functional materials. Herein, we summarize the previous progress on light-color, broad-spectrum, and nanomodifications on lignin and its applications in natural sunscreen, as well as drug loading, UV-blocking, and anti-UV-aging properties. Additionally, several obstacles and corresponding solutions in future UV-blocking application of lignin are proposed.

In this chapter, the catalytic effects and properties of dendrimer and dendritic macromolecules in alcohol fuel cells are discussed. Dendrimers are highly branched macromolecules that contain spaces. Thanks to this hollow structure of dendrimers, nanocomposite materials are encapsulated, making electrocatalytic activity more efficient in direct alcohol fuel cells (DAFCs). The toxic reaction caused by platinum damages the alcohol cells and shortens the life of the fuel cell. For this purpose, materials such as carbon-based nanocomposites and nanocomposites of alloys with transition metals are reinforced with dendrimers and DAFCs become more efficient. The effects of dendrimers on the cell by reinforcing platinum with alloys of nanocomposite materials in direct alcohol fuel cells are reported. © 2021 Elsevier Inc. All rights reserved.

The chapter exemplifies the in-depth analytical characterization of variously structured synthetic and bio-macromolecules by a combination of the fundamental hydrodynamic approaches, i.e., analytical ultracentrifugation, intrinsic viscosity, translation diffusion, and size exclusion chromatography resolving the essential macromolecular characteristics—molar mass and hydrodynamic size as well as their distribution, shape, and conformation.

Dendrimers are a selected class of macromolecules including structurally hyperbranched nanopolymers with globular shapes. Specific properties such as nanometric size, low polydispersity index, transport capacity of molecules, total control in their preparation, good solubility, and in some cases high biocompatibility make them attractive materials for various applications. For several years, dendrimers have been proposed as drug delivery systems as their chemical characteristics such as versatile terminal groups allow them to conjugate with multiple drugs either covalently or by supramolecular interactions; with an adequate targeting agent they can enhance the efficacy of classical treatments. In the present chapter, we describe the different properties of dendrimers highlighting the characteristics that are helpful in nanotechnology applied to the design of drug delivery systems.

The structure and dynamics of proteins in solution are closely related to their activity and, ultimately, to their performance in products and technologies, for example, drug formulations and enzymatic catalysis. With this in mind, the study of the fundamental behavior of proteins in deep eutectic solvents not only provides insight into a novel alternative to aqueous and molecular organic solvents, but also contributes to understanding the potential behavior of these macromolecules in non-aqueous environments. In particular, it has relevance for systems with high levels of dehydration, liquid phases for dispersions at cryogenic temperatures, or systems with high ionic strength. In this chapter, we will explore current knowledge of the physicochemical behavior of proteins in deep eutectic solvents. The local and global structure of proteins in these solvents will be presented and compared to those in aqueous solutions, organic solvents and ionic liquids. Furthermore, the characteristic behavior of proteins in deep eutectic solvents will be linked to solvation effects and the interaction of the macromolecules with the solvent, where specific electrostatic and hydrogen bond interactions can affect the structure and dynamics of proteins. Finally, challenges and opportunities in the field will be discussed, with the aim of guiding a common effort to develop a better understanding of the fundamental behavior of proteins in these interesting environments.

Ionic liquid belongs to the class of organic salt with melting temperature, generally below 100 °C. Those having melting point below room temperature are termed as room temperature ionic liquid. Throughout the last few decades, ionic liquids have drawn large attention to the scientists due to amazing tunable nature regarding their chemical structure and remarkable properties. Through the extensive research work on the structure and application of ionic liquids, newer generation of ionic liquid has arrived which showed excellent biological properties and proved to be efficient as a component in various drug delivery systems. This chapter deals with the biologically active ionic liquids, which are known as 3rd generation ionic liquid. Firstly, we discuss on the interaction of ionic liquids with important biological macromolecules. It is followed by the discussion on the application of ionic liquids in different biomedical domain like antimicrobial activity, anticancer activity and ionic liquid in drug delivery system or as active pharmaceutical ingredients. The potential of ionic liquid conjugates consisting protein or carbohydrates are also discussed. Finally, the polymeric form of ionic liquid is briefly highlighted with a view of future perspective.

Frontal affinity chromatography (FAC) is a versatile method to analyze biomolecular interactions in terms of dissociation constants (Kds). The application of FAC to lectin-oligosaccharide interaction analysis is particularly important because it is a key process for elucidating the complex features of glycans, the third class of bioinformative macromolecules; global features of glycans remain more elusive than those of nucleic acids and proteins. Considering that an increasing number of lectins as well as carbohydrate-recognition domains/modules have been investigated both via genome search and by chance, systematic analysis of their basic properties, including oligosaccharide specificity, is crucial. Reinforced FAC is a unique method enabling highly reproducible interaction analysis, typically between fluorescently labeled oligosaccharides and immobilized lectins in a high-throughput manner, whereby even weak interactions (e.g., Kd > 10− 4 M) can be determined precisely by a simple procedure with a small amount of labeled oligosaccharides (~ 1 pmol).

Polyisobutylene is a unique, fully saturated polymer with a variety of useful properties ranging from outstanding biocompatibility and barrier behavior to high thermal, oxidative, and chemical stability. This chapter provides a brief overview on endfunctional polyisobutylenes (PIBs) prepared by quasiliving carbocationic polymerization (QLCCP) of isobutylene and on the applications of the resulting terminally functionalized PIBs by us as macroinitiators and macromonomers to create novel macromolecular architectures not existed earlier. These include novel ABA triblock and ABCBA pentablock copolymers and polymer conetworks, such as amphiphilic and cyanoacrylate-telechelic PIB-based conetworks with various high added value application possibilities, such as ion conducting membranes, robust pH-reponsive hydrogels, nanohybrids as highly efficient nanocatalysts, elastic wound closure films, etc.

Several dendrimer-based contrast agents have been properly designed for in vivo specific diagnostic applications, displaying high flexibility for the molecular imaging of organs and other target-specific locations. Dendrimers are prepared with a level of control not reachable with most linear polymers, leading to nearly monodisperse, globular macromolecules with a large number of peripheral groups and an internal cavity able to encapsulate a payload. In particular, the abundance of functional groups on the outer shell serves as a platform for multifunctional attachment not only of imaging agents but also specific targeting groups and solubility modifiers. Small variations in dendrimer size, also in the nanoscale dimension, result in considerable changes in terms of biodistribution, pharmacokinetics, and excretion. Such modifications enable the dendrimer-based contrast agents to localize preferentially to areas or organs of interest for facilitating target-specific imaging as well as assume excretion pathways that do not interfere with desired applications. Moreover, the numerous attachment sites available on dendrimers have triggered new synthetic chemistry techniques for the development of multimodality imaging agents. In this chapter, the synthesis and practical usage of dendrimer-based contrast agents for the major imaging modalities are discussed focusing mainly on the chemical design as applied to radionuclide, computer tomography, magnetic resonance, optical and multi-modality imaging.

Gene delivery is a remarkable and novel method to treat different types of diseases, including genetic disorders and cancer. The foremost hindrance that lowers the in vivo applications of this approach is the intact transportation of large negatively charged and fragile molecules to cellular nuclei. The current advancements in nanotechnology favor the development of novel delivery systems based on RNA or DNA molecules. Such systems are proving to be effective substitutes for viral vectors and are formed of materials such as carbon nanotubes, liposomes, inorganic nanoparticles, nanoscale polymeric peptides, and protein-based nanoparticles. They have an advantage over viral vectors for target specificity, low biological cytotoxicity, plasticity in design, and reduced immune response. This chapter provides a comprehensive overview of macromolecular delivery systems based on nanotechnology.

Chitosan and its derivatives have been widely explored as polymeric drug carriers in biomedical research due to their biocompatibility, biodegradability, nontoxicity, and low-cost production from renewable resources. At low pH values (i.e., below its pKa of 6.5), the primary amines of chitosan remain positively charged and can spontaneously interact with polyanions to form a polyelectrolyte complex (PEC). The fabrication process of PECs is simple and performed under mild conditions without using any chemical cross-linker, surfactants, or organic solvents. Therefore the chitosan-based PECs are well-tolerated and ideal carriers for the delivery of susceptible drugs and macromolecules. In this chapter, an overview of chitosan, including its general structure, sources, and physicochemical properties, is presented. This chapter also discusses the mechanism of PECs formation, general preparation procedure, and various extrinsic and intrinsic factors affecting the formation and stability of PECs. Finally, the recent developments in chitosan-based PECs and their applications in drug delivery, gene delivery, and tissue engineering are discussed in detail.

Lanthanide biochemistry has experienced a revival in recent years owing to the discovery of new biomolecular platforms that are amenable to bind, sequester, or transport lanthanide ions. This has inherently created a need for physicochemical methods that report on lanthanide-containing macromolecular systems. In this chapter, the use of spectrophotometric methods to study the stability of lanthanide-macromolecule complexes in solution is discussed. Indeed, lanthanide ions have unique spectral properties in the ultraviolet, visible, and near-infrared domains that set them apart from the more common elements encountered in biochemistry, and these unique features can be leveraged to study, in a quantitative and robust manner, the solution chemistry of their biorelevant species (Kd, pH stability, temperature profile, etc.). This chapter aims at bringing a method that has been established and validated in the small molecule chemistry field to this new era of lanthanide biochemistry.

Lignin is an aromatic polymer with great potential for the preparation of polymeric nanoparticles as this macromolecule is inexpensive, stable, relatively nontoxic, and highly biodegradable. Over the years, the development of lignin nanoparticles has been a subject of great interest to the scientific community as promising vehicles for important biomedical applications (e.g. drug and gene delivery, biomedical imaging), due to their ability to adsorb, encapsulate, or conjugate bioactive compounds within or onto their surface. Furthermore, lignin presents phenolic and aliphatic hydroxyl groups that can be chemically modify with targeting molecules, such as pH-sensitive polymers and targeting ligands, allowing a pH-responsive drug release and an increased cellular interaction with specific cells, respectively. In this chapter, the most important fabrication methods to obtain lignin nanoparticles such as, antisolvent precipitation, solvent exchange, sonication, and interfacial polymerization and cross-linking as well as the lignin nanoparticles functionalization approaches toward their use in biomedical applications, especially as drug and gene delivery vehicles will be discussed.

Dendrimers because of their three-dimensional hyperbranched structures are among the most interesting topics in the last two decades. They are monodisperse, nanosize, and multifunctional macromolecules and have generation- and surface-dependent properties in aqueous media. Besides their advantages, they have some issues in biomedical applications such as positive charge-induced cytotoxicity and deep penetration into cell mass in therapeutics. These issues can be overcome by conjugation of their surface with targeting and imaging ligands or hybridization them with different nanoparticles (NPs). This helps dendrimers to be more efficient in therapeutic applications such as smart targeted cell treatment, bioimaging, drug and gene delivery, and so on. In this chapter, we cover the most important hybridization of dendrimers with different NPs including graphene, carbon nanotubes (CNTs), carbon quantum dots (CQDs), gold NPs (AuNPs), gadolinium-based NPs, mesoporous silica NPs (MSNs), upconversion NPs (UCNPs), etc. and their applications in therapeutics.

Biological macromolecules are naturally occurring polymers and are visualized as a replacement for nonbiodegradable polymers by the researchers. These natural macromolecules are bestowed with excellent properties of biodegradability, biocompatibility, and low cost. Nowadays, these polymers are being exploited for engineering nanostructured hybrid materials and formulations that have unique applications in therapeutics as well as diagnostics. Among all biological macromolecules, polysaccharides are preferred due to their structural characteristics and self-assembling ability, which provide ease in making hierarchical nanostructures. Microbes, in particular fungi, are rich sources of a variety of polysaccharides, due to the presence of some extremely strong polysaccharides in their cell walls. These polysaccharides, in addition to providing physical strength to fungal cells, also mediate cellular communication and act as an adhesion scaffold for other cells. Some examples of fungal-derived polysaccharides that exhibited diverse biological activities are pullulan, yeast glucan, lentinan, scleroglucan, schizophyllan, and auricularian. The current chapter comprehensively describes the structural and synthesis details of fungal polysaccharides. Further, it also throws light into the fabrication of different nanomaterials using these fungal polysaccharides along with their biomedical applications.

Advances in the research and development of segmented conjugated macromolecules continue to open opportunities in the design of materials for a multitude of applications. Careful choice of polymerization technique enables the synthesis of controlled structures using precursors with promising mechanical and electrochemical properties. Further modification of the macromolecular structures allows for additional functionalities such as flexible side chains for process ability. Electrochemical properties of polymers are tuned using and combining segments with appropriate properties, for example, combining electron donor and acceptor properties to control the electronic band gap in materials for photovoltaics. This contribution will describe representative examples of conjugated systems and respective applications, differentiate between the oligomer and the polymer approach, and describe select developments in segmented conjugated polymer systems for use in a variety of electro-optical applications.

The fundamental research on the driving forces of three phase partitioning (TPP) is reviewed here. The behavior, such as interfacial adsorption, dilatational and shear rheological properties of the interfacial film in the case of few model proteins were discussed in TPP systems. The rheological properties and the composition of the middle layer formed by the model proteins in TPP have been outlined. The results of this research were used to frame a supposed mechanism for TPP as follows. The emulsification of the components of the TPP systems enables the proteins, and other amphipathic macromolecules to adsorb at the interface of the immiscible liquid phases, form a viscoelastic layer on the surface of the emulsion droplets, thus stabilizing it, and finally the system creams, aggregates into an emulsion gel, in which the protein is enriched. Therefore, it is suggested that those substances can be efficiently purified by TPP which quickly form a strong, viscoelastic film at the interface (by adsorption and/or fast conformational changes, formation of lateral bonds) under the conditions of the given partitioning systems.

Dendrimers are very small-sized macromolecules with a well-defined and hyperbranched structure which offers high variety of surface functionality. They are polyvalent and this feature provides different kinds of interactions with other components depending on the chemical nature of terminal groups. Nowadays different kinds of dendrimers with various surface-ending groups and different surface charges (negative, positive, and neutral) are established. Dendrimers with high density of surface active groups can be easily functionalized by different moieties including therapeutic agents, targeting ligand, solubilizing agents, imaging and diagnostic units through different strategies. Chemical modification of dendrimer's surface is an easy way to engineer and control their biological interactions. The well-defined molecular structure and their spherical construction provide an attractive architecture for dendrimers and they can be used as multifunctional vector for drug delivery applications.