Oxidized starch cross-linked porous collagen-based hydrogel for spontaneous agglomeration growth of adipose-derived stem cells.

Many strategies have been employed to artificially reconstruct adipose tissue in tissue engineering. The functionalization and survival of reconstructed adipose tissue depend on sufficient angiogenesis. Notably, agglomeration growth of adipose-derived stem cells (ASCs) is beneficial to promoting angiogenesis. Herein, we present a porous collagen-based hydrogel for spontaneous agglomeration growth of ASCs to promote angiogenesis. Oxidized starch with different oxidation degree was prepared and used to cross-link collagen to fabricate the porous hydrogel. The gelation time and pore size of hydrogels can be controlled by adjusting the oxidation degree of starch. Crosslinking enhances the mechanical properties, inhibits the swelling and biodegradation of the hydrogels. The hydrogels possess good blood compatibility and cytocompatibility. Significantly, ASCs tended to adhere to the hydrogels and spontaneously grew into spheres along with time. Effective expression of vascular endothelial growth and fibroblast growth factors were observed. Overall, the hydrogels have application prospects in vascularized adipose tissue engineering.

Synthesis of silver nanoparticles using oxidized amylose and combination with curcumin for enhanced antibacterial activity.

Many kinds of multi-drug-resistant microorganisms have appeared. Moreover, monotherapy is increasingly no longer adequate for many complicated bacterial infections. Therefore, development of efficient combination antibacterial agent is becoming crucial. Herein, we present a hybrid antibacterial agent with enhanced antibacterial activity and high aqueous dissolubility based on silver nanoparticles and curcumin. The silver nanoparticles were firstly synthesized using oxidized amylose as an environmentally friendly reducing agent and stabilizer. Then, curcumin was added into the above mixture to get the hybrid antibacterial agent. The hybrid antibacterial agent presented high dissolubility in aqueous solution and enhanced antibacterial activity. In addition, the hybrid antibacterial agent presented good antioxidant activity and cell compatibility. Overall, the developed hybrid antibacterial agent has a potential to combat multiple bacteria-induced infections of wound surfaces.

Preparation and characterization of dialdehyde ß-cyclodextrin with broad-spectrum antibacterial activity.

Consumers demand more alternatives of riskless antibacterial agents to prevent microbial contamination in food industry. Oxidized carbohydrate may be a potential option as new antibacterial agent. However, the relatively weak antibacterial property of oxidized carbohydrate is not satisfactory. In this paper, dialdehyde ß-cyclodextrins with different oxidation degree were prepared by periodate oxidation and their antibacterial properties were systematically studied. The results showed that multi-aldehyde groups were successfully introduced into ß-cyclodextrin molecules by periodate oxidation. The aqueous solubility and stability of dialdehyde ß-cyclodextrins were improved as expected. It is interesting that dialdehyde ß-cyclodextrins possessed outstanding antibacterial activity against both Gram-positive and Gram-negative bacteria. The minimal inhibitory concentrations against E. coli, S. aureus and B. subtilis reached 0.63, 1.25 and 0.63 mg/mL, respectively. Moreover, dialdehyde ß-cyclodextrins effectively inhibited bacterial growth on the surface of apples. The results demonstrated that oxidized oligosaccharide with multi-aldehyde groups and good dispersibility in aqueous solution possessed satisfactory antibacterial activity, which can be used as new antibacterial agent in food industry.

Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent.

Using oxidized amylose as carrier of linalool for the development of antibacterial wound dressing.

This study aimed to prepare antibacterial wound dressings based on collagen and linalool/oxidized amylose inclusion complex. Encapsulation with oxidized amylose was used as an effective way to introduce linalool into collagen matrix. Our results showed that the content of linalool in the composite dressings was efficiently increased thanks to the solubilization effect of oxidized amyloses. The developed composite dressings possessed porous structure. They had abilities to keep the wound in moist environment and meanwhile prevent the excess exudates accumulation. The incorporation of linalool conferred the composite dressings with excellent antibacterial activities as expected. Moreover, the composite dressing with the highest content of linalool presented enhanced blood compatibility and good cell biocompatibility. This composite dressing effectively promoted granulation tissue formation and accelerated wound healing. It effectively prevented inflammation in regenerated skin tissue and scar formation too. Overall, the developed antibacterial wound dressings hold great potential for use in wound healing applications.