The Influence of an Isocyanate Structure on a Polyurethane Delivery System for 2′-Deoxycytidine-5′-monophosphate

Abstract

The delivery of nucleosides represents an interesting research trend in recent years due to their application in various viral infections. The main aims of this study were to develop and to characterize polyurethane particles that are intended to be used for the transport of nucleosides. Three samples have been prepared using aliphatic diisocyanates, a mixture of polyethylene glycol, polycaprolactone, and diols, respectively. The samples were characterized through refractivity measurements, drug loading efficacy, release and penetration rate investigations, FTIR and Raman spectroscopy, thermal analyses, Zetasizer, SEM, HDFa cells viability, and irritation tests on mice skin. The results indicate the obtaining of particles with sizes between 132 and 190 nm, positive Zeta potential values (28.3–31.5 mV), and a refractivity index around 1.60. A good thermal stability was found, and SEM images show a medium tendency to agglomerate. The samples’ color, pH, and electrical conductivity have changed only to a small extent over time, and the evaluations indicate an almost 70% encapsulation efficacy, a prolonged release, and that around 70% of particles have penetrated an artificial membrane in the first 24 h. The synthesized products should be tested in further clinical trials, and the current tests on cell cultures and mice skin revealed no side effects.

Polyurethane Microstructures for 2′-Deoxycytidinic Acid Delivery: Preparation and Preliminary Characterization

“…In the current study, the highest value was registered for the second sample, with GDA (67.8%); a value that is comparable to those reported in the literature [21,23]. The DCSS release profile from PU microstructures that were maintained in SBF medium exhibited a fast phase in the first 20 h and then the cumulative percentage increased slowly from 47 to 58% (sample_1) and from 51 to 61% (sample_2) in the next 24 h. It must be noted that the degradation of PU microstructures and their release profile can be easily modified by using various polyether/polyester ratios in their synthesis [23].…”

“…The proliferation and adhesion of various cells to polymer biomaterials such as polyethyleneimine, polypropyleneimine, polypyrrole, and poly(p-phenylenediamine) were reported two decades ago [ 41 ]. Zanetta et al [ 42 ] have found that PU foams can be used as a support material for the proliferation of mesenchymal stem cells, while our previous study has revealed the same behavior [ 23 ]. In the current research, the cell viability data demonstrate the compatibility of the carrier with the cellular environment and highlight the fact that PU microstructures at the tested concentration are suitable as a delivery system for DCSS.…”

“…A new variant of a polyurethane carrier was synthesized through spontaneous emulsification combined with the formation of macromolecular chains based on a procedure described in our previous studies [ 23 , 24 ]; the polyaddition process between an aqueous phase (PCL, BD, and PEG in double-distilled water, were sonicated using a homogenizer for 15 min) and an organic phase (IPDI in acetone dissolved under the same conditions) was based on the recipe described in Table 1 . Tween ® 20 was used as an emulsifying agent, and DCSS as an active biological compound, whereas GDA was added only to the second sample.…”

“…The cumulative drug release (CDR) was assessed by maintaining the PU microstructures in a simulated body fluid (SBF), which was prepared according to the T. Kokubo recipe [ 26 ] for 60 h. The procedure has been described in one of our previous articles [ 23 ]: a 1.5 mL aqueous solution of each sample (0.88 mg/mL) was added to a 30 mL SBF. Three 0.5 mL aliquots were withdrawn every 12 h and analyzed for drug content using spectrophotometry at 271 nm.…”

Surface Properties of a Biocompatible Thermoplastic Polyurethane and Its Anti-Adhesive Effect against E. coli and S. aureus

“…A very versatile biomaterial used in medical applications such as catheters, wound dressings, coatings, and drug delivery systems is represented by polyurethane (PU) [23][24][25][26], in particular by thermoplastic PU (TPU). This polymer is composed of soft and hard segments, polyols and isocyanates, respectively [24,26], whose proportions determine a different degree of flexibility, toughness, and softness [23] and confer good mechanical properties.…”