Search results for "drug delivery."

Biodegradable hydrogels obtained by photocrosslinking of dextran and polyaspartamide derivatives

2003

The functionalization of dextran with glycidyl methacrylate (GMA) leads to the formation of a derivative that generates hydrogels for irradiation at 365nm. The effects of various polymer concentrations and irradiation times on the yield and the properties of the obtained hydrogels are reported. The networks have been characterized by FT-IR spectra, dimensional analysis and swelling measurements carried out at different pH values. In vitro studies suggest that all samples undergo a partial chemical hydrolysis, whereas the incubation with dextranases causes a total degradation whose rate depends on the degree of crosslinking. In addition, aqueous solutions of functionalized dextran have been …

DRUG DELIVERY FROM MUCOADHESIVE DISKS BASED ON A PHOTO-CROSS-LINKABLE POLYASPARTAMIDE DERIVATIVE

2005

Disks for local delivery of amoxicillin to the buccal or gastric cavity were prepared using as starting polymer a polyaspartamide derivative. In particular, α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) was derivatized with glycidyl methacrylate (GMA) in order to synthesize PHG, a photo-cross-linkable and biodegradable polymer that gives rise to the formation of a chemical hydrogel (PHG-UV) by UV irradiation. This hydrogel was shaped as disks whose mucoadhesive properties have been confirmed by swelling measurements in phosphate buffer/citric acid solution at pH 7.0 in the presence of various concentrations of mucin. Swelling ability of PHG-UV disks was also evaluated in simulated saliva…

The baculovirus display technology--an evolving instrument for molecular screening and drug delivery.

2008

High throughput screening is a core technology in drug discovery. During the past decade, several strategies have been developed to screen (poly)peptide libraries for diverse applications including disease diagnosis and profiling, imaging, as well as therapy. The recently established baculovirus display vector system (BDVS) represents a eukaryotic screening platform that combines the positive attributes of both cell and virus-based display approaches, allowing presentation of complex polypeptides on cellular and viral surfaces. Compared to microbial display systems, the BDVS has the advantage of correct protein folding and post-translational modifications similar to those in mammals, facili…

Toward Mechanistic Design of Surrogate Buffers for Dissolution Testing of pH-Dependent Drug Delivery Systems

2020

The in vivo dissolution of enteric-coated (EC) products is often overestimated by compendial in vitro dissolution experiments. It is of great interest to mimic the in vivo conditions as closely as possible in vitro in order to predict the in vivo behavior of EC dosage forms. The reason behind this is the overly high buffering capacity of the common compendial buffers compared to the intestinal bicarbonate buffer. However, a bicarbonate-based buffer is technically difficult to handle due to the need for continuous sparging of the media with CO2 to maintain the desired buffer pH. Therefore, bicarbonate buffers are not commonly used in routine practice and a non-volatile alternative is of inte…

NEW BIODEGRADABLE HYDROGELS DESIGNED FOR COLONIC DRUG DELIVERY: IN VITRO RELEASE OF THE PEPTIDES GLUTATHIONE AND OXYTOCIN

2009

Direct chemical grafted curcumin on halloysite nanotubes as dual-responsive prodrug for pharmacological applications

2016

Covalently functionalized halloysite nanotubes (HNTs) were successfully employed as dual-responsive nanocarriers for curcumin (Cur). Particularly, we synthesized HNT-Cur prodrug with a controlled curcumin release on dependence of both intracellular glutathione (GSH) and pH conditions. In order to obtain HNT-Cur produgs, halloysite was firstly functionalized with cysteamine through disulphide linkage. Afterwards, curcumin molecules were chemically conjugated to the amino end groups of halloysite via Schiff's base formation. The successful functionalization of halloysite was proved by thermogravimetric analysis, FT-IR spectroscopy, dynamic light scattering and scanning electron microscopy. Ex…

Histidine-rich glycoprotein-induced vascular normalization improves EPR-mediated drug targeting to and into tumors

2018

Tumors are characterized by leaky blood vessels, and by an abnormal and heterogeneous vascular network. These pathophysiological characteristics contribute to the enhanced permeability and retention (EPR) effect, which is one of the key rationales for developing tumor-targeted drug delivery systems. Vessel abnormality and heterogeneity, however, which typically result from excessive pro-angiogenic signaling, can also hinder efficient drug delivery to and into tumors. Using histidine-rich glycoprotein (HRG) knockout and wild type mice, and HRG-overexpressing and normal t241 fibrosarcoma cells, we evaluated the effect of genetically induced and macrophage-mediated vascular normalization on th…

Smart materials meet multifunctional biomedical devices:Current and prospective implications for nanomedicine

2017

With the increasing advances in the fabrication and in monitoring approaches of nanotechnology devices, novel materials are being synthesized and tested for the interaction with biological environments. Among them, smart materials in particular provide versatile and dynamically tunable platforms for the investigation and manipulation of several biological activities with very low invasiveness in hardly accessible anatomical districts. In the following, we will briefly recall recent examples of nanotechnology-based materials that can be remotely activated and controlled through different sources of energy, such as electromagnetic fields or ultrasounds, for their relevance to both basic scien…

Highly efficient transport of carboxyfluorescein diacetate succinimidyl ester into COS7 cells using human papillomavirus-like particles

2003

AbstractHuman papillomavirus virus-like particles (VLPs) have recently been used to deliver genes into mammalian cells in vitro and in vivo. Here, we investigated whether VLPs may serve as an efficient carrier of low molecular weight compounds (e.g. hormones, vitamins, peptides etc.) into cells. COS7 cells were incubated with recombinant HPV-16L1/L2 VLPs labelled with the fluorescence dye carboxyfluorescein diacetate succinimidyl ester. Using flow cytometry, we demonstrate that labelled VLPs can specifically bind to the cell surface followed by their complete internalisation. Our results indicate that VLPs are promising vehicles for highly efficient delivery of low molecular weight compound…

Hyaluronic acid based hydrogels for antibiotics and enzymes release: from academic research to industry

2016

Conclusion: HA-g-PDLLA hydrogel is suitable to coat a prosthesis remaining adherent to it and distributing itself in the bone cavity. The hydrogel has been proven effective in a rabbit model of highly contaminated implant. In vivo studies have demonstrated how the intraoperative coating of implants with DAC is safe and feasible. HA-EDA-MA hydrogel is able to protect PEP from alteration during storage and it seems a good candidate for a potential once-daily oral formulation in the treatment of celiac disease.