Constructing safe and durable antibacterial textile surfaces using a robust graft-to strategy via covalent bond formation

Challenges and Potential Solutions for 100% Recycling of Medical Textiles

Medical textiles are all fiber-based products and structures which are utilized for emergency treatment, clinical, surgical and hygienic purposes. It is an exceptionally particular and bio viable specialized material, utilized for clinical and cleanliness applications. Volumes of clinical waste being created in excess of 60 million tons yearly around the world. According to the current investigation reports and information, the worldwide clinical waste administration market was esteemed at USD 11.77 billion in the year 2018 and will reach at 17.89 billion by the year 2026 at a compound annual growth rate (CAGR) of 5.3%. Over the world, out of the measure of waste created by medical care activities, about 85% is general waste and staying 15% is viewed as unsafe material that might be irresistible, poisonous or radioactive. The following particular reasons are very harmful for the environment in the upcoming future. The waste management policy of medical textile is a vital fact for the world. The potential and effectual solution is recycling of these medical wastes. Current solutions for 100% recycling of medical textiles are chemical treatment, incineration, and autoclaving. But the most innovative solution of medical textiles is molecular tagging/tagging of fibers. Medical textile market is producing state-of-the-art polymeric textile implantable devices that are redefining traditional materials and methods of surgery. Developing polymer innovation has yielded a wide scope of uses of implantable clinical material or biotextiles. Due to world Covid-19 pandemic situation, the requirement of medical textiles already has been increased almost double from last year. It has been observed that the market value of medical textiles will be in optimum position. In the year 2019, the global market worth of medical textiles was US$ 17.5 billion. In the present world, the current medical textiles like implantable and non-implantable categories are not applying for recycling process or end used of their life cycle. In this paper, we will discuss about potential solutions for recycling medical textiles like—by using conductive polymers, maintaining ε-Poly-lysine, non-fibrous biomass, bioactive fibers, etc. But there are still some challenges for recycling like—maintain 100% polymeric bonds, bacterial effect, flexibility and sustainability for clinical performance after recycling the specific product. In this paper, we are presenting the scientific methods, mechanisms, and procedures that used to overcome the aforementioned challenges in the recycling methods.

In Situ Functionalization of Cellulose with Zinc Pyrithione for Antimicrobial Applications

Considering the public health demands for stronger and effective personal protective clothing, herein, antimicrobial fabrics using a known bacteriostatic and fungistatic drug zinc pyrithione (ZPT) have been reported. ZPT was synthesized in situ on cellulosic fabric, viscose (VC), using a zinc metal precursor and 2-mercaptopyridine-N-oxide as a ligand (VC-ZPT). For comparison, viscose was also phosphorylated (VP) before in situ functionalization with ZPT (VP-ZPT). Both approaches provided adequate protection from microbes; however, functionalization of cellulose with phosphate (VP) resulted in the formation of a linking group between cellulose and ZPT, which exhibited better uniformity of ZPT over the fabric surface and higher durability to washing. The functionalization was confirmed by inductively coupled plasma mass spectroscopy (ICP-MS), scanning electron microscopy (SEM), and Raman spectroscopy. Further, the bonding of phosphate with ZPT was confirmed by ³¹P solid-state NMR. The physical properties, such as appearance, bending length, and mechanical strength, of the treated fabrics remained unchanged. The antimicrobial activities of VP-ZPT with VC-ZPT were studied against Escherichia coli, Staphylococcus aureus, and Candida albicans, which were found to be effective until 20 laundry cycles in VP-ZPT. Additionally, VP-ZPT samples exhibited poor adherence of bacteria on the fabric surface. The functionalized fabrics may find applications for topical skin diseases in reducing the necessity of repeated use of antibiotic ointments.

Highly efficient and durable antibacterial cotton fabrics finished with zwitterionic polysulfobetaine by one-step eco-friendly strategy

In this work, a novel formulation of polysulfobetaine, poly (sulfobetaine-acrylamide-allyl glycidyl ether) (PSPB-AM-AGE), was synthesized and grafted onto cotton. The synthesis of PSPB-AM-AGE and its grafting on the cotton fabrics were confirmed by FTIR, XPS and SEM. The PSPB-AM-AGE treated cotton fabrics exhibited a high level of antibacterial rate against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which are 95.18% and 98.74%, separately, as well as a good laundry durability. The mechanical tests showed that the essential cotton properties can be largely preserved in the treatment process. Moreover, the hydrophilicity, air and water permeability of the cotton were improved after treated with PSPB-AM-AGE, indicating a better wearing comfort performance. The whiteness of the cotton fabrics did not decrease significantly. The safety evaluation demonstrated that PSPB-AM-AGE had no cytotoxicity. The developed antibacterial finishing introduced a new method to apply polysulfobetaine interfaced on cellulose, providing great potential for biomedical fabric application.

Self-Assembled Lecithin/Chitosan Nanoparticles Based on Phospholipid Complex: A Feasible Strategy to Improve Entrapment Efficiency and Transdermal Delivery of Poorly Lipophilic Drug

PURPOSE

Lecithin/chitosan nanoparticles have shown great promise in the transdermal delivery of therapeutic agents. Baicalein, a natural bioactive flavonoid, possesses multiple biological activities against dermatosis. However, its topical application is limited due to its inherently poor hydrophilicity and lipophilicity. In this study, the baicalein-phospholipid complex was prepared to enhance the lipophilicity of baicalein and then lecithin/chitosan nanoparticles loaded with the baicalein-phospholipid complex were developed to improve the transdermal retention and permeability of baicalein.

METHODS

Lecithin/chitosan nanoparticles were prepared by the solvent-injection method and characterized in terms of particle size distribution, zeta potential, and morphology. The in vitro release, the ex vivo and in vivo permeation studies, and safety evaluation of lecithin/chitosan nanoparticles were performed to evaluate the effectiveness in enhancing transdermal retention and permeability of baicalein.

RESULTS

The lecithin/chitosan nanoparticles obtained by the self-assembled interaction of chitosan and lecithin not only efficiently encapsulated the drug with high entrapment efficiency (84.5%) but also provided sustained release of baicalein without initial burst release. Importantly, analysis of the permeation profile ex vivo and in vivo demonstrated that lecithin/chitosan nanoparticles prolonged the retention of baicalein in the skin and efficiently penetrated the barrier of stratum corneum without displaying skin irritation.

CONCLUSION

These results indicate the potential of drug-phospholipid complexes in enhancing the entrapment efficiency and self-assembled lecithin/chitosan nanoparticles based on phospholipid complexes in the design of a rational transdermal delivery platform to improve the efficiency of transdermal therapy by enhancing its percutaneous retention and penetration in the skin.

Surface-Anchored Metal-Organic Framework-Cotton Material for Tunable Antibacterial Copper Delivery

In the present study, a new copper metal-organic framework (MOF)-cotton material was strategically fabricated to exploit its antibacterial properties for postsynthetic modification (PSM) to introduce a free amine to tune the physicochemical properties of the material. A modified methodology for carboxymethylation of natural cotton was utilized to enhance the number of nucleation sites for the MOF growth. Subsequently, MOF Cu3(NH2BTC)2 was synthesized into a homogenous surface-supported film via a layer-by-layer dip-coating process. The resultant materials contained uniformly distributed 1 μm × 1 μm octahedral MOF crystals around each carboxymethylated fiber. Importantly, the accessible free amine of the MOF ligand allowed for the PSM of the MOF-cotton surface with valeric anhydride, yielding 23.5 ± 2.2% modified. The Cu2+ ion-releasing performance of the materials was probed under biological conditions per submersion in complex media at 37 °C. Indeed, PSM induces a change in the copper flux of the material over the first 6 h. The materials continue to slowly release Cu2+ ions beyond 24 h tested at a flux of 0.22 ± 0.003 μmol·cm-2·h-1 with the unmodified MOF-cotton and at 0.25 ± 0.004 μmol·cm-2·h-1 with the modified MOF-cotton. The antibacterial activity of the material was explored using Escherichia coli by testing the planktonic and attached bacteria under a variety of conditions. MOF-cotton materials elicit antibacterial effects, yielding a 4-log reduction or greater, after 24 h of exposure. Additionally, the MOF-cotton materials inhibit the attachment of bacteria, under both dry and wet conditions. A material of this type would be ideal for clothing, bandages, and other textile applications. As such, this work serves as a precedence toward developing uniform, tunable MOF-composite textile materials that can kill bacteria and prevent the attachment of bacteria to the surface.