Electrostatically Assembled Multilayered Films of Biopolymer Enhanced Nanocapsules for on-Demand Drug Release

Abstract

We describe layer-by-layer (LbL) buildup and pH-responsive behavior of multilayer films of alginate/chitosan/ alginate -modified silica nanocapsules (SNCs) and chitosan (CS) biopolymers via electrostatic interaction. The SNC/CS films exhibit pH-triggered swelling/deswelling transitions under physiological conditions. Fulvestrant, an FDA-approved selective estrogen receptor down-regulator agent for the treatment of breast cancer, was encapsulated in SNCs and further incorporated into the LbL films. The drug release profile from the films was dependent on pH value of the surrounding environment. At pH 7.4, the films were able to efficiently entrap fulvestrant, with only ∼38% released in 120 days, whereas exposure to a lower pH value (pH 5.0) triggered faster fulvestrant release in phosphate buffer solution at 37 °C. Atomic force microscopy and ellipsometry showed that the films retained their structural integrity in PBS after several swelling/ deswelling cycles. SNC/CS LbL films demonstrated repeated on/off drug release under external triggers, allowing consistent fulvestrant release (∼14−18% of encapsulated fulvestrant released for each cycle) over a 10-day period without significant change in drug release rate. This work demonstrates the first proof-of-concept platform of SNC-incorporated films with welldefined internal structure, good stability, high loading capacity, and controlled/sustained release profile for on-demand drug delivery. With great versatility to use various active compounds and building blocks, the films may have high potential for broad applications such as implantable biosensors and antifouling coatings.

Polyelectrolyte-Coated Mesoporous Bioactive Glasses via Layer-by-Layer Deposition for Sustained Co-Delivery of Therapeutic Ions and Drugs

“…Despite this assumption, the assessment of the homogeneous coating on the spherical surface of the particles and the coating thickness cannot be clearly evaluated by using FE-SEM images. In fact, the thickness of the multi-layer system is usually evaluated by ellipsometric measurements or Atomic Force Microscopy (AFM) after the deposition on a flat substrate, which allows the homogeneous coating of the surface [43]. However, FE-SEM observations confirmed that the LbL procedure and the subsequent ibuprofen loading did not significantly affect the morphology of both the particles.…”

“…At variance, this band is clearly not detectably visible for the Cu_SG_CIC spectrum, most likely due to the low quantity of loaded ibuprofen. In the last region of the spectra (1369-1458) the peaks can be imputed to CH 2 bending of the chitosan, alginate, and ibuprofen [41,43].…”

Nanomaterial-Based Therapy for Wound Healing

“…The formulations might be minimized by reducing NP doses. Primarily, the addition of adjuvants with a lower price or formulating composite NPs can boost the therapeutic efficiency [154]. Second, specific or sustained drug delivery and release can be exploited, such as microneedle methods, NP layered self-assembly, and controlled release of laden medicines maintained by nanoscale systems [155][156][157].…”

Atomic Force Microscopy (AFM) on Biopolymers and Hydrogels for Biotechnological Applications—Possibilities and Limits

“…Zhang et al investigated in detail the grooves on alginate microfibers prepared by microfluidic spinning in different concentrations of alginate in deionized water [ 167 ]. Alginate/chitosan/alginate-modified silica nanocapsules and chitosan multilayer films were investigated during pH-triggered swelling and deswelling, and topography measurements by AFM were used to verify that their structural integrity in PBS was maintained [ 168 ].…”