Peptide loaded polymeric nanoparticles by non-aqueous nanoprecipitation.

It is always a challenge to encapsulate water-soluble peptides in polymer nanoparticle (NP) systems. We establish and validate our newly developed non-aqueous nanoprecipitation method to encapsulate neuro-peptides drugs such as oxytocin and Luteinizing hormone-releasing hormone (LHRH) in poly(sebacic anhydride) (PSA) NPs. NPs were prepared by a solvent-antisolvent process under a strict anhydrous environment to obtain high drug loading and to avoid premature PSA degradation and drug release.

Biodegradable Breast Tissue Marker Clip.

Biodegradable soft tissue biopsy clips have been developed as implants with the potential to serve as visual markers for regions suspected to contain tumor growth in the breast. These clips are multidimensional tissue markers with better biocompatibility and imaging features. The clips were prepared using biodegradable polymers, poly(l-lactide--ε-caprolactone) and methoxy polyethylene glycol--l-lactide, that contain iodixanol or barium sulfate as contrast agents; they are further coated with hyaluronic acid or sodium alginate hydrogels.

Effect of Ethylene Oxide and Gamma (γ-) Sterilization on the Properties of a PLCL Polymer Material in Balloon Implants.

Poly-l-lactide--ε-caprolactone (PLCL) is a unique polymer containing both polylactic acid and poly-ε-caprolactone (PCL) chain units, and thus it has better flexible and biodegradable properties. Based on these unique properties of PLCL, we have developed balloons that are now widely used in treating major medical problems [ 109-116]. One of the most important considerations needed for balloons is to ensure that the material properties remain similar after undergoing ethylene oxide (EtO) or gamma (γ-) sterilization treatments.

In vitro and in vivo degradation behavior and the long-term performance of biodegradable PLCL balloon implants.

Biodegradable poly(l-lactide-co-ε-caprolactone) (PLCL) are used to prepare inflatable balloon implants in treating rotator-cuff injuries and tissue separation. These balloon implants act as a temporary spacer for tissues, while reducing pain and allowing rehabilitation after surgery. It is essential to ensure that each balloon fulfill two requirements after implantation: (1) display a well-defined degradation profile, and (2) remain unaffected by premature rapture or leakage.

Injectable Biodegradable Multimodal Mammography Marker.

Introducing temporary markers for imaging studies is an idea, which in the proper clinical settings can be advantageous for patient compliance and in selected cases where a permanent marker is nondesirable. Hence, we developed injectable marker formulation using a biodegradable "pasty polymer" of poly(ricinoleic acid--sebacic acid) (PSA:RA) containing iodixanol and iron oxide as contrast agents that can serve as a visual marker for the region suspected to have tumor growth. The goal of this work is to noninvasively evaluate the visibility, shape, and degradation of the injectable PSA:RA formulation using magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound (US).

Biodegradable implantable balloons: Mechanical stability under physiological conditions.

Rotator cuff tendons injuries occurs as a result of trauma, e.g. due to falling, mechanical injuries and frequent overhead activity and as natural degenerative tears in elderly people.

Biodegradable inflatable balloons for tissue separation.

Confining radiation to a specific region (during radiation therapy) minimizes damage to surrounding tissues. Biodegradable inflatable balloons (bio-balloons) were developed. The device protects the normal tissues by increasing the gap between radiation source and critical structures.

Alternating Poly(ester-anhydride) by Insertion Polycondensation.

We report on a synthetic method where polyanhydride is used as starting material and the ester monomers are inserted through complete esterification, leading to an alternating ester-anhydride copolymer. The molar ratio of ricinoleic acid (RA) and sebacic acid (SA) was optimized until polysebacic acid is completely converted to carboxylic acid-terminated RA-SA and RA-SA-RA ester-dicarboxylic acids. These dimers and trimers were activated with acetic anhydride, polymerized under heat and vacuum to yield alternating RA-SA copolymer.

Stable polyanhydride synthesized from sebacic acid and ricinoleic acid.

Poly(anhydride) are unstable and prone to hydrolytic degradation and depolymerisation via anhydride interchange. They are stored at -20°C, packed under inert atmosphere until use. We synthesized a new poly(anhydride) from ricinoleic (RA) and sebacic (SA) acid with alternating ester-anhydride structure that is stable at 25°C for over 18months.

Biocompatibility and safety of PLA and its copolymers.

PLA and its copolymers are commonly used for a wide variety of applications. While they are considered to be biocompatible, side effects resulting from their implantation have been reported. The implantation of biomaterials always results in a foreign body reaction.

Castor Oil-Based Biodegradable Polyesters.

This Review compiles the synthesis, physical properties, and biomedical applications for the polyesters based on castor oil and ricinoleic acid. Castor oil has been known for its medicinal value since ancient times. It contains ∼90% ricinoleic acid, which enables direct chemical transformation into polyesters without interference of other fatty acids.

Long-term Local and Systemic Safety of Poly(L-lactide-co-epsilon-caprolactone) after Subcutaneous and Intra-articular Implantation in Rats.

The use of biodegradable materials is gaining popularity in medicine, especially in orthopedic applications. However, preclinical evaluation of biodegradable materials can be challenging, since they are located in close contact with host tissues and might be implanted for a long period of time. Evaluation of these compounds requires biodegradability and biocompatibility studies and meticulous pathology examination.

Interspecies differences in reaction to a biodegradable subcutaneous tissue filler: severe inflammatory granulomatous reaction in the Sinclair minipig.

Soft tissue filler products have become very popular in recent years, with ever-increasing medical and aesthetic indications. While generally considered safe, the number of reported complications with tissue fillers is growing. Nevertheless, there is no specific animal model that is considered as the gold standard for assessing safety or efficacy of tissue fillers, and there are very little data on interspecies differences in reaction to these products.

In vivo degradation and elimination of injectable ricinoleic acid-based poly(ester-anhydride).

The in vivo degradation and elimination after subcutaneous implantation of injectable p(SA-RA) 3:7 copolymer in rats, followed by characterization of the polymer matrix composition during hydrolysis and erosion, is reported. Major chemical changes were observed during the first few days post implantation, the anhydride bonds hydrolyzed along with about 45% weight loss and a significant decrease in the molecular weight. 1H NMR spectral analysis was used to determine the structures and content of ricinoleic acid containing oligomeric chains present in the degraded polymer.