Facile synthesis of PDMAEMA-coated hollow mesoporous silica nanoparticles and their pH-responsive controlled release

Synthesis of pH-sensitive poly (N,N-dimethylaminoethyl methacrylate)-grafted halloysite nanotubes for adsorption and controlled release of DPH and DS drugs

“…These unique features of HNTs result in their numerous applications in medicine, such as capturing flowing cells [3], bone implants [4], and drug delivery systems [5]. The first studies on the release behavior of HNTs showed that release rate of tetracycline HCl, khellin, and nicotinamide are diminished [10][11][12][13][14][15][16][17][18][19][20] times in comparison with the pure drug crystals [6]. Control of release rate by modification of [7,8].…”

“…Among the various pH-responsive polymers, poly (N, N-dimethylaminoethyl methacrylate) (PDMAEMA) as a weak polybase with pK a =7. 3-7.5 and specific characteristics of antibacterial and biocompatibility has been considered largely in delivery of active biological agents like gene and protein [19][20][21]. Amine groups of PDMAEMA are positively charged in the protonated state and can interact electrostatically with DNA, enzyme, and drugs with negative charge [22].…”

“…This characteristic behavior was used by Sun et al in controlled release of rhodamine B (RhB) from PDMAEMA-coated mesoporous silica nanoparticles prepared by surface-initiated ATRP (SI-ATRP) [24]. Yu et al also studied the controlled release of doxorubicin hydrochloride (DOX) from PDMAEMA-coated hollow mesoporous silica nanoparticles prepared by SI-ATRP [19]. They showed that the PDMAEMA chains coated at the external surface act as a storage gate which can switch in response to pH.…”

“…TEM micrograph for (A) HNT and (B, C, D, and E) HNT-PDMAEMA-1 with various magnifications3.2. pH-responsive behavior of HNT-PDMAEMA-1PDMAEMA chains consist of tertiary amine groups and therefore are a weak electrolyte (pK a ≈7.3)[19]. This means that amine groups are protonated considerably at pH values lower than 7.…”

Grafting of pH-sensitive poly (N,N-dimethylaminoethyl methacrylate-co-2-hydroxyethyl methacrylate) onto HNTS via surface-initiated atom transfer radical polymerization for controllable drug release

“…The pH-sensitivity of PDMAEMA is due to presence of ionizable tertiary amine groups with pK a of 7.3 which can be protonated at low pH conditions and lead to a pronounced change in polymer hydrophilicity upon protonation and deprotonation [6][7][8].…”