Dendrimers have widely been adopted as drug and gene delivery vehicles, which include dendrimer-drug conjugates, drug encapsulation, and gene complexation. Recent advances in dendrimer formulations have the potential to create new therapeutic products and enable novel combination therapies.
Dendrimers differ fundamentally from their linear analogs, resulting in distinct physical properties. Unlike linear polymers, dendrimers can be synthesized with precise structural control through repetitive covalent synthesis, yielding monodisperse and structurally perfect molecules.
We offer custom synthesis of functionalized sulfonimide-based dendrimers, as illustrated in Figure 1. Our in-house Building Block Collection includes over 100 functionalized arylsulfonyl chlorides, ideal for the rational design of functionally diverse dendrimers. The core and peripheral decorations can be selected on request.
Please, contact us at orders@lifechemicals.com for any additional information and price quotations.
For further information on our dendrimer synthesis, please, refer to the Publications by Life Chemicals team
Figure 1. Representative structures of the sulfonimide-based dendrimers and dendrons.
Main characteristics of dendrimers
Dendrimers possess distinct structural characteristics, including nanoscopic size, a highly branched architecture, a multifunctional surface, and a spacious interior, making them ideal candidates as drug delivery vehicles. Unlike traditional linear polymers, dendrimers are monodisperse, highly symmetrical, and feature surface polyvalency [1-2]. The repetitive growth reactions during their synthesis result in higher generations and increased branching, culminating in a three-dimensional, spherical structure [1]. The synthetic process allows precise control over dendrimer size, surface charge, peripheral functional groups, and solubility [3]. For example, higher-generation dendrimers have larger sizes, more extensive interior cavities, and an increased number of terminal functional groups.
Synthesis of dendrimers
One of the simplest and most reliable methods for synthesizing ‘designer’ dendrimers involves the selective mono- or bis-sulfonylation of primary amines with arylsulfonyl chlorides. Repeating these reactions enables the construction of selectively decorated and variably shaped dendrimers from basic building blocks. This approach offers several advantages, including a wide availability of arylsulfonyl chlorides, high chemical stability of sulfonamides, and the ease of product purification through recrystallization, making the production of multigram quantities straightforward. Additionally, complete or selective sulfonylation can be used to functionalize the periphery of commercial amine-based dendrimers like POPAM and PAMAM. Additional functional groups of arylsulfonyl moieties further expand the potential for customizing dendrimers for various applications.
Dendrimers in medical applications and as drug delivery vehicles
Current dendrimer research primarily focuses on their applications in diagnostics and therapeutics, such as in vivo contrast agents for X-ray and magnetic resonance imaging, gene delivery systems, and materials for antibody production and corneal wound repair.
Many therapeutic agents face such challenges as low aqueous solubility and short half-lives, necessitating the development of efficient drug delivery systems. Dendrimers have emerged as a crucial class of nanostructured carriers in nanomedicine, offering versatile solutions for drug and gene delivery.
Due to their structural diversity and adaptability, dendrimers have been employed in various delivery strategies. For instance, dendrimers with a hydrophobic core and hydrophilic periphery can function as unimolecular micelles, effectively solubilizing hydrophobic drugs by entrapping them within their intramolecular cavities [4-5]. Cationic dendrimers have been widely used as non-viral gene carriers [6]. Additionally, dendrimer surface groups can be conjugated with drugs and other functional moieties. Conjugation with polymers, for example polyethylene glycol (PEG), polysaccharides, and polypeptides enhances the stability and solubility of therapeutics [7].
Dendrimer-drug conjugates offer several advantages, including reduced systemic effects and increased efficacy at targeted sites compared to free drugs [4, 8]. Additionally, drug conjugation with dendrimers has been shown to extend the half-life of therapeutics.
Dendrimers in material sciences
Their large size and customizable peripheral functionality make dendrimers valuable for assembling nano- and mesoscopic hierarchical structures, which are of significant interest in materials science. For example, dendrimers offer an effective method for producing highly efficient phosphorescent materials that can be processed from solution. Given their broad utility in both primary and applied science, the focus of dendrimer synthesis has shifted from maximizing the number of generations to achieving precise control over their shape and selective functionalization.
References:
- Tomalia DA, Hedstrand DM, Ferritto MS. Comb-burst dendrimer topology: new macromolecular architecture derived from dendritic grafting. Macromolecules. 1991;24:1435–8.
- Abbasi E, Aval SF, Akbarzadeh A, Milani M, Nasrabadi HT, Joo SW, et al. Dendrimers: synthesis, applications, and properties. Nanoscale Res Lett. 2014;9:247.
- Vögtle F, Richardt G, Werner N. Introduction. In: Vögtle F, Richardt G, Werner N, editors. Dendrimer chemistry: concepts, syntheses, properties, applications. Wiley: Academic; 2009. p. 1–24.
- Menjoge AR, Kannan RM, Tomalia DA. Dendrimer-based drug and imaging conjugates: design considerations for nanomedical applications. Drug Discov Today. 2010;15:171–85.
- Rao BN, Viswanath V, Reddy KR, Fathima SR, Surekha P, Bhuvaneswari S. Dendrimers–structure, synthesis, encapsulation, characterization and application. J Global Trends Pharm Sci. 2015;6:2860–6.
- Parekh HS. The advance of dendrimers–a versatile targeting platform for gene/drug delivery. Curr Pharm Design. 2007;13:2837–50.
- Liu J, Gray WD, Davis ME, Luo Y. Peptide- and saccharide-conjugated dendrimers for targeted drug delivery: a concise review. Interface Focus. 2012;2:307–24.
- Kolhe P, Khandare J, Pillai O, Kannan S, Lieh-Lai M, Kannan RM. Preparation, cellular transport, and activity of polyamidoamine-based dendritic nanodevices with a high drug payload. Biomaterials. 2006;27:660–9.