Polydopamine-Based Simple and Versatile Surface Modification of Polymeric Nano Drug Carriers

Abstract

The surface of a polymeric nanoparticle (NP) is often functionalized with cell-interactive ligands and/or additional polymeric layers to control NP interaction with cells and proteins. However, such modification is not always straightforward when the surface is not chemically reactive. For this reason, most NP functionalization processes employ reactive linkers or coupling agents or involve pre-functionalization of the polymer, which are complicated and inefficient. Moreover, pre-functionalized polymers can lose the ability to encapsulate and retain a drug if the added ligands change chemical properties of the polymer. To overcome this challenge, we use dopamine polymerization as a way of functionalizing NP surfaces. This method includes brief incubation of the pre-formed NPs in a weak alkaline solution of dopamine, followed by secondary incubation with desired ligands. Using this method, we have functionalized poly(lactic-co-glycolic acid) (PLGA) NPs with three representative surface modifiers: a small molecule (folate), a peptide (Arg-Gly-Asp), and a polymer [poly(carboxybetaine methacrylate)]. We confirmed that the modified NPs showed the expected cellular interactions with no cytotoxicity or residual bioactivity of dopamine. The dopamine polymerization method is a simple and versatile surface modification method, applicable to a variety of NP drug carriers irrespective of their chemical reactivity and the types of ligands.

NIR‐Activated Polydopamine‐Coated Carrier‐Free “Nanobomb” for In Situ On‐Demand Drug Release

“…The TEM images of DNPs@PDA and DNPs/N@PDA in Figure 2A clearly indicated that the nanoparticles consisted of a lot of small spherical domains. Thus, the as‐prepared nanoparticles were formed through the secondary aggregation of small nanoparticles from DNPs via surface‐deposited PDA 21. The zeta potential was measured to investigate the surface modification and charge changes of the DNPs (Figure 2B).…”

“…Recent studies reported that the dopamine could self‐polymerize to form surface‐adherent polydopamine (PDA) films onto a wide range of materials either organic or inorganic by a spontaneous oxidation reaction in an alkaline solution (pH = 8.5) 18, 19, 20, 21. It was widely used as material surface modification since the PDA shells are stable enough to reach the target cells after intravenous injection 22, 23.…”

Immobilization of Thermostable Lipase QLM on Core-Shell Structured Polydopamine-Coated Fe3O4 Nanoparticles

“…As shown in Scheme 1, Fe 3 O 4 nanoparticles were first coated with a polydopamine layer via the polymerization of dopamine under alkaline conditions, and the immobilization of thermostable lipase QLM was conducted through the Schiff base reaction between amine groups of lipase and polydopamine as described previously [30]. Arpanaei et al once constructed a poly(acrylic acid)-coated Fe 3 O 4 cluster@SiO 2 for lipase immobilization, in which complicated procedures were performed through the covalent attachment via N-(3-dimethyl aminopropyl)-N-ethyl carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) chemistries [21].…”

“…The catechol/quinone in polydopamine could facilitate adhesion and deposition on solid surfaces through chelation or hydrogen bonding, which has been used for the coating of polydopamine layers on various colloidal particles [29]. After the coating of a polydopamine layer on solid surfaces, enzyme immobilization or its conjugation with functional ligands possessing nucleophilic groups (e.g., amine and thiol) can be easily achieved through Michael addition and/or Schiff base reactions [30]. Through this method, trypsin, heparin, and albumin have been successfully immobilized on cellulose paper, polyethylene membrane, magnetic nanoparticles, etc.…”

Polydopamine-based Materials as Carriers for Drug Delivery

“…Furthermore, the in vivo anti-tumor effects study showed that injecting DTX-loaded Gal-pD-TPGS-PLA/NPs reduced the tumor size most significantly on hepatoma-bearing nude mice [18]. Yeo et al functionalized poly(lactic-co-glycolic acid) (PLGA) NPs with folate, Arg-Gly-Asp, and poly(carboxybetaine methacrylate) as surface modifiers, which showed no cytotoxicity [19].…”