Semiconducting, biodegradable and bioactive fibers for drug delivery

Abstract

Abstract. In this work we present the drug release properties and morphological studies of fibers formed by mixing different ratios of poly(lactic acid) (PLA) and poly(3-thiophene methyl acetate) (P3TMA) loaded with four drugs (ciprofloxacin, chlorhexidine dihydrochloride, triclosan and ibuprofen sodium salt). Thus, the main aim of this study is to prove that the excellent cellular response of PLA-P3TMA biocompatible scaffolds can be successfully combined with essential applications as drug carrier and delivery systems. Atomic force microscopic (AFM) and scanning electron microscopic (SEM) micrographs of PLA-P3TMA fibers indicate that the presence of the conducting polymer inside the PLA matrix affects the surface morphology, resulting in a significant increment of the bulk conductivity with respect to PLA fibers. Electrospun hybrid fibers of PLA and P3TMA successfully load both hydrophilic and hydrophobic drugs, the release profiles depending on the release environment (i.e. the release rate increases with the hydrophobicity of the medium). Finally, our results prove that the antibacterial activity of the drugs is not affected by their interactions with the PLA-P3TMA matrix.

Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) thermoresponsive microspheres: The low drug loading ensures the pulsatile release mechanism

“…1 H-NMR spectra of poly (NIPAAm-co-NVP) were recorded in deuterated water on a Varian Mercury Plus 400/Varian VXR 200 spectrometer (Rheinstetten, Germany) operating at 400 MHz frequency. The co-monomer molar ratio in the poly(NIPAAmco-NVP) copolymer was calculated according to Equations (1) and (2):(1) (2) where X and Y are the molar fractions of NVP and NIPAAm, respectively. Equation 1represents the area of the methylene protons of NVP (6) at 3.28 ppm and Equation 2describes the peak area (A) at 3.91 ppm of the methynic protons of NVP and NIPAAm (3 and 4).…”

“…One of the most important achievements in drug therapy is the development of controlled release or retard pharmaceutical formulations [1][2][3]. These systems have the advantage of maintaining a constant drug concentration in blood and tissues with a single dose, thereby reducing the frequency of administration and increasing the therapeutic efficacy as well as the patient compliance.…”

Antimicrobial Electrospun Fibers of Polyester Loaded with Engineered Cyclic Gramicidin Analogues

“…Thus, appropriate selection of the processing conditions is required to avoid the formation of droplets and electrospun beads. The procedure used for such optimization, which was individually applied for each mixture, was detailed in previous works [20,21].…”

“…Although recent advances have facilitated the use of different stimuli, such as light, magnetic and electric fields, ultrasounds and electrochemical signals, to trigger drug release from smart material formulations (e.g., films, micro-and nanoparticles, and implant devices) [3][4][5][6], traditional systems based on the biodegradability of polymeric vehicles remain the most employed technology because of its efficiency, simplicity, and low cost [7][8][9][10][11][12][13][14]. Biodegradable polyester particles and fibers are widely employed for controlled and sustained targeted release of hydrophobic and poorly-water soluble drugs [15][16][17][18][19][20][21].…”

Adherability and weldability of poly(lactic acid) and basalt fibre-reinforced poly(lactic acid)

“…PLA can be used to produce bottles, disposable cutlery, biodegradable bags and even clothes that can be used at room temperature because of its acceptable mechanical properties [1][2][3]. PLA is often used as the base material of absorbable stitches and retainers (mainly screws and grafts that facilitate tissue growth), as well as controlled drug delivery systems [4,5]. Nowadays PLA is also increasingly used to manufacture engineering products, although its rigidity and high shrinkage limit its use for products which are exposed to high stresses [1][2][3].…”