<p>Burgeoning Polymer Nano Blends for Improved Controlled Drug Release: A Review</p>

Abstract

With continual rapid developments in the biomedical field and understanding of the important mechanisms and pharmacokinetics of biological molecules, controlled drug delivery systems (CDDSs) have been at the forefront over conventional drug delivery systems. Over the past several years, scientists have placed boundless energy and time into exploiting a wide variety of excipients, particularly diverse polymers, both natural and synthetic. More recently, the development of nano polymer blends has achieved noteworthy attention due to their amazing properties, such as biocompatibility, biodegradability and more importantly, their pivotal role in controlled and sustained drug release in vitro and in vivo. These compounds come with a number of effective benefits for improving problems of targeted or controlled drug and gene delivery systems; thus, they have been extensively used in medical and pharmaceutical applications. Additionally, they are quite attractive for wound dressings, textiles, tissue engineering, and biomedical prostheses. In this sense, some important and workable natural polymers (namely, chitosan (CS), starch and cellulose) and some applicable synthetic ones (such as poly-lactic-co-glycolic acid (PLGA), poly(lactic acid) (PLA) and poly-glycolic acid (PGA)) have played an indispensable role over the last two decades for their therapeutic effects owing to their appealing and renewable biological properties. According to our data, this is the first review article highlighting CDDSs composed of diverse natural and synthetic nano biopolymers, blended for biological purposes, mostly over the past five years; other reviews have just briefly mentioned the use of such blended polymers. We, additionally, try to make comparisons between various nano blending systems in terms of improved sustained and controlled drug release behavior.

Prevascularized Micro-/Nano-Sized Spheroid/Bead Aggregates for Vascular Tissue Engineering

“…The structure of blood vessels is distinct for each of them [30,31]. Large vessels including arteries and veins are composed of three main microscopic wall layers: an outer layer made up of collagen fibers and elastic tissue, a middle layer encompassing collagen fibers, elastic tissue and smooth muscle, and an inner layer comprising endothelium [32][33][34]. Arteries contain more percentage of elastic tissue than veins that enables them to enhance their blood conduction capacity as the blood pressure increases [35].…”

Applications of polymer blends in drug delivery

“…Such systems can be obtained by methods such as communition, mixing of colloids (e.g., latex polymer dispersions), or phase separation (e.g., from solution, dispersions or melt processed polymer blends). Polymeric mixed micelles, which are formed by the assembly of two or more amphiphilic block copolymers [55,70], may also be included in this class of polymer blends. The increase in unit surface area relative to that of particulate level blends results in the interfacial region having a greater influence on interpolymer interactions.…”

“…1). The scientific literature on the application of polymer blends in pharmaceutical products, excipients, and drug delivery systems has mostly focused on specific properties or applications of polymer blends such as miscibility [35,36], film coating [37,38], orally disintegrating films [39], matrix tablets [40][41][42], solid dispersions [43][44][45], biodegradable systems [46,47], transdermal drug delivery [48], environmentally responsive systems [49,50], and modifying or improving the performance of natural polymers [51][52][53][54][55]. Polymer blends have been used in recently emerging pharmaceutical processing techniques such as 3D printing [56][57][58] and electrospinning [59][60][61].…”

On-Demand Drug Delivery Systems Using Nanofibers

“…Single-phase material structures are among the most frequently produced blended NFs [46]. Single-phase fibers consist of only one structure, which can be composed of, but not limited to, one material or a combination of one material and a bioactive component [47]. An appropriate technique for drug loading should be devised based on the characteristics of the drug to achieve optimal drug release kinetics [48].…”