Polysaccharide hydrogels for modified release formulations.

We demonstrate that ''nanofactory''-loaded biopolymer capsules placed in the midst of a bacterial population can direct bacterial communication. Quorum sensing (QS) is a process by which bacteria communicate through small-molecules, such as autoinducer-2 (AI-2), leading to collective behaviors such as virulence and biofilm formation. In our approach, a ''nanofactory'' construct is created, which comprises an antibody complexed with a fusion protein that produces AI-2. These nanofactories are entrapped within capsules formed by electrostatic complex- ation of cationic (chitosan) and anionic (sodium alginate) biopolymers. The chitosan capsule shell is crosslinked by tripolyphosphate (TPP) to confer structural integrity. The capsule shell is impermeable to the encapsulated nanofac- tories, but freely permeable to small molecules. In turn, the capsules are able to take in substrates from the external medium via diffusion, and convert these via the nanofac- tories into AI-2, which then diffuses out. The exported AI-2 is shown to stimulate QS responses in vicinal Escherichia coli. Directing bacterial population behavior has potential appli- cations in next-generation antimicrobial therapy and path- ogen detection. We also envision such capsules to be akin to artificial ''cells'' that can participate in native biological signaling and communicate in real-time with the human microbiome. Through such interaction capabilities, these ''cells'' may sense the health of the microbiome, and direct its function in a desired, host-friendly manner. Biotechnol. Bioeng. 2013;110: 552-562.

/pdf/encapsulated-fusion-protein-confers-sense-and-respond-34cib49qk1.pdf

Encapsulated fusion protein confers "sense and respond" activity to chitosan-alginate capsules to manipulate bacterial quorum sensing.

We have previously reported the preparation of the genipin cross-linked alginate-chitosan (GCAC) microcapsules composed of an alginate core with a genipin cross-linked chitosan membrane. This paper is the further investigation on their structural and physical characteristics. Results showed that the GCAC microcapsules had a smooth and dense surface and a networked interior. Cross-linking by genipin substantially reduced swelling and physical disintegration of microcapsules induced by nongelling ions and calcium sequestrants. Strong resistance to mechanical shear forces and enzymatic degradation was observed. Furthermore, the GCAC membranes were permeable to bovine serum albumin and maintained a molecular weight cutoff at 70 KD, analogous to the widely studied alginate-chitosan, and alginate-poly-L-lysine-alginate microcapsules. The release features and the tolerance of the GCAC microcapsules in the stimulated gastrointestinal environment were also investigated. This GCAC microcapsule formulation offers significant potential as a delivery vehicle for many biomedical applications.

/pdf/genipin-cross-linked-polymeric-alginate-chitosan-127f92vn67.pdf

Genipin Cross-Linked Polymeric Alginate-Chitosan Microcapsules for Oral Delivery: In-Vitro Analysis

In this study, we examined the in-vivo characteristics of a novel microencapsulated thalidomide formulation in a murine model of experimental Crohn's disease. Crohn's disease was induced with a single intra-colonic injection of 120 mg/kg of bodyweight of 2,5,6-trinitrobenzene sulfonic acid (TNBS) dissolved in 30% ethanol in Balb/c mice. Level of tumor necrosis factor alpha (TNF-α), interleukin one beta (IL-1β), interleukin 6 (IL-6) and nitric oxide (NO) were measured in tissue homogenate. Moreover, myeloperoxidase (MPO) activity was determined to assess the extent of neutrophil infiltration. Dose response study showed that treating the mice with microencapsulated thalidomide (100 mg/kg of bodyweight) for two weeks significantly decreased the degree of intestinal inflammation related to Crohn's disease. Higher and lower doses (0, 25, 50 and 200 mg/kg of bodyweight) did not exhibit comparable effects. The present study validates the success of alginate-poly-L-lysine-alginate (APA) microcapsules containing thalidomide in reducing colonic inflammation, and proposes a potential remedy for Crohn's disease.

Use of artificial cell microcapsule containing thalidomide for treating TNBS-induced Crohn's disease in mice.

1. Even though current treatments for inflammatory bowel disease are effective, adverse reactions remain a problem. With the intention of developing a new drug delivery system, we attempted to identify molecules that are selectively adsorbed to inflamed bowel. 2. The PhD-C7C phage display peptide library was used for biopanning against mouse isolated bowel, either untreated (control) or with inflammation caused by ischaemia-reperfusion injury. One hundred clones were selected from among those obtained by two biopanning procedures and the amino acid sequences of these clones were identified by determination of the base sequences. 3. Then, 20 clones were selected by an alignment process, after which the three clones with the highest affinity for inflammatory bowel were identified. One of these three clones had significantly higher affinity for inflammatory bowel than for normal bowel. 4. In conclusion, biopanning against isolated bowel samples identified an amino acid sequence (SQSHPRH) with a specific high affinity for inflammatory bowel.

Identification of ligands binding specifically to inflammatory intestinal mucosa using phage display.

Recent research and clinical evidence suggest that thalidomide could potentially be used to treat inflammation associated with Crohn's disease. However, systemic side effects associated with large doses of this drug have limited its widespread use. Treatment with thalidomide would prove more efficacious if the drug could be delivered directly to target areas in the gut, thereby reducing systemic circulation. Microcapsule encapsulation could enable direct delivery of the drug. To assess the latter, we designed and tested drug-targeting release characteristics of alginate-poly-L-lysine-alginate (APA) microcapsules in simulated gastrointestinal environments. The results show that APA capsules enabled delivery of thalidomide in the middle and distal portions of the small intestine. We also compared the APA membrane formulation with an earlier designed alginate chitosan (AC) membrane thalidomide formulation. The results show that both APA and AC capsules allow for successful delivery of thalidomide in the gut and could prove beneficial in the treatment of Crohn's disease. However, further research is required.

A new method for targeted drug delivery using polymeric microcapsules: implications for treatment of Crohn's disease.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Trisnawati Halim

Author Tools

Chat about Author

Papers

A new method for targeted drug delivery using polymeric microcapsules: implications for treatment of Crohn's disease.