• MeSH
• fibroiny analýza   chemie   MeSH
• konformace proteinů MeSH
• molekulární struktura MeSH

• MeSH
• fibroiny chemie   MeSH
• hmyzí proteiny chemie   MeSH
• Lepidoptera MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

Larvae of many lepidopteran species produce a mixture of secretory proteins, known as silk, for building protective shelters and cocoons. Silk consists of a water-insoluble silk filament core produced in the posterior silk gland (PSG) and a sticky hydrophilic coating produced by the middle silk gland (MSG). In Bombyx mori, the fiber core comprises three proteins: heavy chain fibroin (Fib-H), light chain fibroin (Fib-L) and fibrohexamerin (Fhx, previously referred to as P25). To learn more about the role of Fhx, we used transcription activator-like effector nuclease (TALEN) mutagenesis and prepared a homozygous line with a null mutation in the Fhx gene. Our characterization of cocoon morphology and silk quality showed that the mutation had very little effect. However, a detailed inspection of the secretory cells in the posterior silk gland (PSG) of mid-last-instar mutant larvae revealed temporary changes in the morphology of the endoplasmic reticulum. We also observed a morphological difference in fibroin secretory globules stored in the PSG lumen of Fhx mutants, which suggests that their fibroin complexes have a slightly lower solubility. Finally, we performed an LC-MS-based quantitative proteomic analysis comparing mutant and wild-type (wt) cocoon proteins and found a high abundance of a 16 kDa secretory protein likely involved in fibroin solubility. Overall, our study shows that whilst Fhx is dispensable for silk formation, it contributes to the stability of fibroin complexes during intracellular transport and affects the morphology of fibroin secretory globules in the PSG lumen.

• MeSH
• bourec * genetika   ultrastruktura   MeSH
• endoplazmatické retikulum metabolismus   ultrastruktura   MeSH
• fibroiny genetika   metabolismus   ultrastruktura   MeSH
• hedvábí * chemie   genetika   MeSH
• mutace MeSH
• mutageneze cílená metody   MeSH
• slinné žlázy * cytologie   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• fibroiny chemie   MeSH
• finanční podpora výzkumu jako téma MeSH
• hmyzí proteiny chemie   MeSH
• můry MeSH
• sekvence aminokyselin MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• srovnávací studie MeSH

Tissue engineering benefits from novel materials with precisely tunable physical, chemical and mechanical properties over a broad range. Here we report a practical approach to prepare Bombyx mori silk fibroin hydrogels using the principle of non-solvent induced phase separation (NIPS). A combination of reconstituted silk fibroin (RSF) and methanol (non-solvent), with a final concentration of 2.5% w/v and 12.5% v/v respectively, maintained at 22 °C temperature turned into a hydrogel within 10 hours. Freeze-drying of this gel gave a foam with a porosity of 88%, a water uptake capacity of 89% and a swelling index of 8.6. The gelation kinetics and the loss tangent of the gels were investigated by rheometry. The changes in the morphology of the porous foams were visualized by SEM. The changes in RSF chemical composition and the relative fraction of its secondary structural elements were analyzed by ATR-FTIR along with Fourier self-deconvolution. And, the changes in the glass transition temperature, specific heat capacity and the relative fraction of crystallinity of RSF were determined by TM-DSC. Data suggested that RSF-water-methanol behaved as a polymer-solvent-non-solvent ternary phase system, wherein the demixing of the water-methanol phases altered the thermodynamic equilibrium of RSF-water phases and resulted in the desolvation and eventual separation of the RSF phase. Systematic analysis revealed that both gelation time and the properties of hydrogels and porous foams could be controlled by the ratios of RSF and non-solvent concentration as well as by the type of non-solvent and incubation temperature. Due to the unique properties we envisage that the herein prepared NIPS induced RSF hydrogels and porous foams can possibly be used for the encapsulation of cells and/or for the controlled release of both hydrophilic and hydrophobic drugs.

• MeSH
• biokompatibilní materiály chemie   MeSH
• bourec chemie   MeSH
• fibroiny chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• hydrogely chemie   MeSH
• poréznost MeSH
• rozpouštědla chemie   MeSH
• teplota MeSH
• tkáňové inženýrství MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Many lepidopteran larvae produce silk secretions to build feeding tubes and cocoons that play important protective roles in their lives. Recent research on the silk of bombycoid and pyralid moths has shown that it contains several highly abundant silk components with remarkable mechanical properties. It was also found to contain a number of other proteins of which the functions have yet to be identified. To gain an overview of the silk composition in more primitive lepidopteran species and to identify the core silk components common to most species, we analyzed the cocoon proteins of Tineola bisselliella, which belongs to the basal ditrysian moth line. Using de novo transcriptome sequencing combined with mass spectrometry (MS)-based proteomics, we detected more than 100 secretory proteins in the silk cocoons. Fibroin, sericins, and protease inhibitors were found to be the most abundant proteins, along with several novel candidate silk components. We also verified the tissue and developmental stage specificity of the silk protein expression and characterized the morphology of both the silk glands and silk in T. bisselliella. Our study provides a detailed analysis of silk in the primitive moth, expands the known set of silk-specific genes in Lepidoptera, and helps to elucidate their evolutionary relationships.

• MeSH
• biologická evoluce * MeSH
• fibroiny metabolismus   MeSH
• hedvábí * chemie   genetika   metabolismus   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• inhibitory proteas metabolismus   MeSH
• larva genetika   metabolismus   fyziologie   MeSH
• můry * genetika   metabolismus   fyziologie   MeSH
• proteomika metody   MeSH
• sericiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Concomitant intake of alcoholic beverages with sustained-release oral formulations may potentially lead to dose dumping. Alcohol-resistance testing is currently a requirement for the manufacturers by regulatory authorities. Silk fibroin produced by silkworm Bombyx mori is suggested in this work as a potential alternative to a narrow spectrum of alcohol-resistant excipients. Oxycodone HCl, tramadol HCl, and flurbiprofen were selected as model drugs and formulated with regenerated silk fibroin either in the form of an amorphous solid dispersion or as a physical mixture and compressed into tablets. Preliminary compactability and tampering-resistance studies were performed. The ethanol-resistance was tested in media containing 5%, 10%, 20%, or 40% (v/v) ethanol concentration. Drug release profiles were compared using f2 similarity factor. Good mechanical tampering-resistance (tensile strength of 14.6 MPa at 400 MPa compression pressure) was obtained for tablets compressed from physical mixture. Tablets compressed from amorphous solid dispersion had lower tensile strength (2.2 MPa) but showed chemical tampering-resistance to extraction by pure ethanol (7.1% of oxycodone HCl after 24 h). Drug release is controlled predominantly by swelling and diffusion. With an increasing ethanol concentration in release medium, the tablets swelled less, resulting in a slower release. This trend was similar for all tested drugs and for both physical states formulations. No dose dumping occurred in the presence of ethanol; therefore, silk fibroin could be considered as an alternative alcohol-resistant excipient for sustained release application.

• MeSH
• fibroiny chemie   MeSH
• léky s prodlouženým účinkem * MeSH
• pomocné látky * MeSH
• tablety MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• bourec genetika   MeSH
• fibroiny genetika   chemie   MeSH
• hmyzí hormony genetika   MeSH
• molekulární sekvence - údaje MeSH
• můry genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční homologie nukleových kyselin MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

In traditional medicine, natural silk is regarded as a cognitive enhancer and a cure for ameliorating the symptoms of heart disease, atherosclerosis, and metabolic disorders. In this review, general characteristics of both silk proteins, fibroin and sericin, extracted from silkworm Bombyx mori and their potential use in the neuronal disorders was discussed. Evidence shows that silk proteins exhibit neuroprotective effects in models of neurotoxicity. The antioxidant, neuroprotective, and acetylcholinesterase inhibitory mechanisms of silk proteins could prove promising in the treatment of neurodegenerative diseases. Owing to their excellent neurocompatibility and physicochemical properties, silk proteins have been used as scaffolds and drug delivery materials in the neuronal tissue engineering. These data support the potential of silk proteins as an effective complementary agent for central and peripheral neurological disorders.

• MeSH
• antiflogistika terapeutické užití   MeSH
• antioxidancia terapeutické užití   MeSH
• antitumorózní látky terapeutické užití   MeSH
• fibroiny terapeutické užití   MeSH
• hedvábí * farmakologie   izolace a purifikace   terapeutické užití   ultrastruktura   MeSH
• hmyzí proteiny * terapeutické užití   MeSH
• hypoglykemika terapeutické užití   MeSH
• lidé MeSH
• neuroprotekce * účinky léků   MeSH
• neuroprotektivní látky * farmakologie   terapeutické užití   MeSH
• neurorehabilitace MeSH
• sekvence aminokyselin MeSH
• sericiny terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH