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Responsive co-polymers based on polyethyleneglycol methacrylate (PEGMA) monomers have been grown by aqueous phase ATRP from a model protein, trypsin, to generate hybrid polymer-protein block conjugates. The conjugates (Hybrids I and II) both contained the same segment of grafted responsive co-polymer to afford a phase transition at 37 °C, Hybrid II however differed from Hybrid I by having a second block of hydrophilic pPEGMA monomer grown from the end of the responsive block. The resultant ‘diblock’ and ‘triblock’ hybrids were characterised in terms of their temperature-dependent behaviour in solution by dynamic light scattering, small-angle neutron scattering and pulsed-gradient spin-echo NMR, and their structures at surfaces examined by aqueous phase atomic force microscopy and cryo transmission electron microscopy. These data showed that Hybrids I and II differed in their solution behaviour with temperature, dependent on the arrangement of their grafted polymer blocks. Hybrid I self-assembled into higher-order structures above 37 °C before precipitating reversibly, whereas Hybrid II remained essentially constant in size across a similar temperature range even when its attached intermediate polymer block underwent a phase transition. The differences in polymer-protein hybrid behaviour were also manifest in enzyme activity assays with temperature-dependent hydrolysis of both peptide and protein substrates varying with hybrid architecture. Overall the data show that it is possible to grow responsive polymer-protein block co-polymers of varied structures, architectures and solution behaviour and that these can be used to control bioconjugate activity

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Wound repair is a complex process that has not been entirely understood. It can conclude in several irregularities. Hence, designing an appropriate wound dressing that can accelerate the healing period is critical. Infections, a major obstacle to wound repair, cause an elevated inflammatory responses and result in ultimate outcome of incomplete and prolonged wound repair. To overcome these shortcomings, there is a growing requirement for antibacterial wound dressings. Dressings with antibacterial activities and multifunctional behaviors are highly anticipated to avoid the wound infection for successful healing. The aim of this review is not only to concentrate on the importance of antibacterial dressings for wound healing applications but also to discuss recent studies and some future perspectives about antibacterial wound dressings.

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In this study, modified kappa-carrageenan/pectin hydrogel patches were fabricated for treatment of buccal fungal infections. For this purpose, kappa-carrageenan-gacrylic acid was modified with different thiolated agents (L-cysteine and 3-mercaptopropionic acid), and the thiol content of the resulting modified kappacarrageenan was confirmed by elemental analyzer. Then, the hydrogel patches were fabricated, and characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, ex vivo mucoadhesion test, and swelling behavior.Triamcinolone acetonide was added either directly or by encapsulating within the poly(lactic-co-glycolic acid) nanoparticles. The release amount of the drug from the directly loaded patch was 7.81 mg/g polymer, while it was 3.28 mg/g polymer for the encapsulated patch with the same content at 7 hr. The hydrogel patches had no cytotoxicity by cell culture studies. Finally, the drug loaded hydrogel patches were demonstrated antifungal activity against Aspergillus fumigatus and Aspergillus flavus.These results provide that the novel modified kappa-carrageenan and pectin based buccal delivery system has promising antifungal property, and could have advantages compared to conventional buccal delivery systems.antifungal activity, buccal drug delivery, thiolated kappa-carrageenan, triamcinolone acetonide | INTRODUCTIONUlcerative diseases in the mucous membrane of the buccal cavity are observed as a result of a wide etiological reasons such like infections, traumas, immunological disorders, or side effects of some drugs. 1,2 Amongst these, mucocutaneous diseases are observed frequently such as lichen planus, 3 aphthous stomatitis, 4 erythema multiforme, and Behçet's disease. 5 Conventional drug applied to the oral mucosa are generally in the form of in situ gels, 6 pastes, 7 or mouthwashes. 8 These forms have some drawbacks due to causing high-level drug concentration and in the oral cavity for a short period of time. 9 Therefore, the desired therapeutic drug concentration for mucosal and transmucosal absorption could not be adequately provided for healing. To overcome the limitations of the conventional delivery systems, use of oral mucoadhesive systems in the topical treatment of oral ulcerative diseases is a more rational approach. The oral mucoadhesive systems could be prepared in various forms such as buccal adhesive patches, films, and tablets. 10,11

The skin is the largest and most exposed organ in the human body. Not only it is involved in numerous biological processes essential for life but also it represents a significant endpoint for the application of pharmaceuticals. The area of in vitro skin tissue engineering has been progressing extensively in recent years. Advanced in vitro human skin models strongly impact the discovery of new drugs thanks to the enhanced screening efficiency and reliability. Nowadays, animal models are largely employed at the preclinical stage of new pharmaceutical compounds development for both risk assessment evaluation and pharmacokinetic studies. On the other hand, animal models often insufficiently foresee the human reaction due to the variations in skin immunity and physiology. Skin-on-chips devices offer innovative and state-of-the-art platforms essential to overcome these limitations. In the present review, we focus on the contribution of skin-on-chip platforms in fundamental research and applied medical research. In addition, we also highlighted the technical and practical difficulties that must be overcome to enhance skin-on-chip platforms, e.g. embedding electrical measurements, for improved modeling of human diseases as well as of new drug discovery and development.

New classes of information-rich DNA block co-polymer conjugates were synthesised, encoded with thermoresponsive and biocompatible poly(tri(ethylene glycol)ethyl ether methacrylate) (pTriEGMA) chains and oligomeric nucleic acids connected by either bioreducible or non-reducible links. The pTriEGMA chains were grown from initiator-functionalised hybridised DNA, designed to assemble with toehold overhangs. Functional information in the conjugates was explored via dynamic light scattering (DLS) and atomic force microscopy (AFM), in order to evaluate (i) reversible self-assembly into supramolecular structures across the pTriEGMA phase transition temperature; (ii) conformational change via addition of competing DNA sequences across the toeholds, and (iii) reductive cleavage of polymer-DNA links. The results showed that discrete nanoscale conjugates could reversibly associate through pTriEGMA phase behaviour and that size and association behaviour in one class of conjugate could be switched by addition of a competing DNA sequence and by reduction to break the polymer-DNA links. Preliminary experiments with the DNA-conjugates as delivery systems for doxorubicin to a cancer cell line indicated good tolerability of the conjugates alone and cytotoxic efficacy when loaded with the drug.