Development of sustained‐release antibacterial urinary biomaterials through using an antimicrobial as an organic modifier in polyurethane nanocomposites

Abstract

Urinary catheters are among the most frequently used medical devices in clinical practice. However, their use is associated with high rates of nosocomial infection. This study investigates the use of polyurethane nanocomposites (PUNCs) incorporating an antimicrobial agent, chlorhexidine diacetate (CHX), behaving as nanoparticle dispersant and model drug/active agent, as sustained-release antibacterial biomaterials in urinary devices. A range of PUNCs incorporating organically modified silicate (OMS) nanoparticles with CHX was fabricated using a solution-cast method. PUNCs with free CHX added into the bulk polymer were also made. Materials were assessed for antibacterial activity in an in vitro urinary tract (UT) model and release kinetics of CHX was studied. PUNCs demonstrated sustained antibacterial activity against Staphylococcus epidermidis in the UT model, reaching ~50 days infection-free in materials with 2 wt % free CHX loading. Drug-release profiles demonstrated that, compared with microcomposite and unfilled polyurethane, the initial burst effect was significantly reduced in PUNCs. Prolonged drug release was achieved through incorporation of OMS, hypothesized to be due to a combination of barrier properties created by the nanoinclusions and strong interactions between CHX and MMT within the PUNCs. Use of PUNCs for sustained drug release in long-term urinary applications shows promise in addressing catheter-related nosocomial infections.

PHB-PEO electrospun fiber membranes containing chlorhexidine for drug delivery applications

“…The FTIR spectra show the characteristic vibrational bands of CHX at 1665 cm -1 corresponding to the C=N-H stretching vibration [27], as well as the absorption bands corresponding to the aromatic C=C stretching located at 1537 and 1490 cm -1 [12]. In this way, the presence of the CHX in the membranes after processing was confirmed [28]. …”

Content-dependent biomineralization activity and mechanical properties based on polydimethylsiloxane–bioactive glass–poly(caprolactone) hybrids monoliths for bone tissue regeneration

“…2 Single inorganic and polymer biomaterials are difficult to meet all the requirements, due to various disadvantages. [5][6][7] BGs have excellent biodegradability, biocompatibility and osteoconductivity, while BG has the ability to form a chemical bonding in contact with living tissue through a bonelike apatite mineral phase. 3,4 Among nanocomposite biomaterials, bioactive glass (BG)based polymer composites have been paid a lot attention recently.…”

Platelet interactions with polyurethane nanocomposites: effect of organic modifier terminal functionality

“…The prepared materials were first examined to assess surface expression of the two modifiers. While it has previously been shown that OMs used to modify silicate layers migrated out of the polymer matrix, altering biological interactions, 15,19 it was hypothesised in this study that OMs were being surface expressed. ToF-SIMS analysis of the two OMSs before incorporation in PEU showed peaks present at 186 and 216 (data not shown).…”

“…Although evidence of 12COOH was not detected on the surface of the PUNCs, we have previously shown migration and release of this OM from the NC system. 15,19 This apparent contradiction can be rationalised by surface energy considerations: when the PU surface is in contact with air, molecules more hydrophobic than the PU are energetically favoured to accumulate at the interface, whereas for hydrophilic molecules, it is energetically unfavourable to be located at the PU/air interface. Thus, methyl terminated OM molecules, which are hydrophobic, can be expected to migrate to the PU/air surface, whereas the hydrophilic COOH terminated OM molecules experience no such driving force, and thus, it is energetically more favourable for them to remain associated with the silicate nanoparticles.…”

“…The OMs were not covalently bound to the silicate layers and can diffuse within the NC system. 15,19 To test the hypothesis that the OMs are able to migrate through the polymer matrix and are being surface expressed, surface analysis was conducted to measure surface expression.…”