Formation and Degradation of Poly(D,L‐lactide) Nanoparticles and Their Potential Application as Controllable Releasing Devices

Abstract

In the presence of surfactant, water-insoluble poly(D,L-lactide) (PLA) was dispersed into narrowly distributed nanoparticles stable in water via microphase inversion. The structure and degradation of such formed nanoparticles were investigated by a combination of static and dynamic laser light scattering. Our results revealed that the degradation rate increased with the temperature and pH so that the degradation could be regulated from minutes to days. Using anionic sodium dodecyl sulfate (SDS) as stabilizer resulted in a slower degradation than using cationic hexadecyltrimethylammonium bromide (HTAB). The phthalocyanine chromophores (PC) could be encapsulated inside these PLA nanoparticles. The degradation of individual PLA nanoparticles led to a controllable releasing of PC. The absorption and fluorescence studies revealed a correlation between the degradation and the releasing of PC. Our results showed that a higher PC/PLA ratio could lead to a faster degradation.

Preparation of poly(lactic acid)/chitosan nanoparticles for anti-HIV drug delivery applications

“…In both the formulations, the drug release rate was higher for alkaline pH than acidic pH, and the drug release in the acidic pH was higher than in the neutral pH. The lower drug release rate in the acidic pH than the alkaline pH is attributed to the repulsion between H + ions and cations on the surface of CS, which slow down the hydrolysis (Proikalis, Tarantalli, & Andreopoulos, 2006;Zhao, Fu, Dennis, & Wu, 2004). SEM images after basic degradation shows that the nanoparticles broken up and released the drug.…”

Powering tyrosol antioxidant capacity and osteogenic activity by biocatalytic polymerization

“…[27][28][29][30][31] PLA is one of the few biodegradable polymers approved for human use by the FDA that has reached the clinical application stage, 32 and offers advantages including commercial availability, low cost and easy purication procedures. Moreover, PLA enables implementation of highly porous nanostructures under suitable preparation conditions.…”

Complementary use of flow and sedimentation field-flow fractionation techniques for size characterizing biodegradable poly(lactic acid) nanospheres

“…The concentration profile is then given by (2) where x is the distance from the accumulation wall and c 0 is the concentration at the wall. The experimental factor that describes the retardation of an analytical zone caused by its compression by the field into the region of slower fluid velocities is the retention ratio R, defined by (3) where v zone is the average velocity of the analyte, and 〈v〉 is the average velocity of the carrier solution. This is experimentally measured as (4) where t 0 is the elution time for a non retained material, or the void time, and t r is the elution time for a retained analyte, or the retention time.…”

“…The size determination of the particles is crucial because different organs are targeted by different sized particles [3]. Nanoparticles, for example, have several advantages over larger micro-particles since they have been proven to be better suited to intravenous delivery.…”

“…Quite recently, two new kinds of nanoparticles have attracted the attention of scientists as promising drug carriers, namely polymeric micelles and dendrimers [2]. However, poly(lactic acid) (PLA) remains one of the most commonly used polymers for drug delivery because its biodegradation leads to pharmacologically inactive substances, which are adsorbed by the body or removed by the metabolism [3].…”