Synthesis, Characterization and Drug Delivery Profile of Magnetic PLGA‐PEG‐PLGA/Maghemite Nanocomposite

Abstract

Summary: The antibiotic cotrimoxazole was associated to the multi-block copolymer containing poly(D,L-lactic-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) segments, PLGA-PEG-PLGA, aiming to reach a controlled drug release system. Block copolymer was synthesized via polycondensation of lactic acid and glycolic acid with PEG in situ. In turn, maghemite was synthesized through the co-precipitation method. The drug cotrimoxazole was inserted in the composite through melting mixing method. Several techniques were used to characterize the materials. The materials were characterized by Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and magnetic force, this last according to the methodology developed by our group. In addition, dissolution profile was studied. These dissolution tests were performed with and without magnetic field, aiming to study the influence of the magnetic field on the dissolution profile. The dissolution was monitored and quantified using the ultraviolet-visible spectrophotometry (UV-Vis), following the USP method for cotrimoxazole tablets. Results demonstrated that nanocomposites presented a good magnetic force, able to keep the magnetic composite trapped in a specific place or tissue. Furthermore, in the presence of a magnetic field, the magnetic nanoparticles were able to perform a magnetic constriction of the material, making the drug release faster than in the absence of the magnetic field. This phenomenon may be useful to perform a fine tuning of the system, allowing the easier adjust of the speed and amount of released drug, useful to improve medical treatments and even the welfare of the patients.

Influence of PLGA and PLGA-PEG on the dissolution profile of oxaliplatin

“…Temperature was kept at 140°C under magnetic stirring for 10 h [29] . The PLGA-PEG block copolymer was synthesized following the same procedure, with addition of commercial PEG (5g) [27] .…”

“…Incomplete release is usual if drugs have interactions with them [25] . The attaching of PEG chains to PLGA may solve these situations [26,27] . The inclusion of PEG into material could also be convenient for improving biocompatibility of the systems [28] .…”

PLA-b-PEG/magnetite hyperthermic agent prepared by Ugi four component condensation

“…XRD results from magnetite, magnetite modified with aldehyde and magnetic composite are shown in Figures 12 curves a)-c) respectively. All the tested materials present peaks at 2" equal to 30.3°, 35.7°, 43.3°, 53.9°, 57.3° and 63.0°, which confirm the spinel structure of the crystal, characteristic of this iron oxide [68], proving that Ugi four component condensation does not change the particles' nature [40,27,69]. Moreover, the crystal size of magnetic particles was calculated by the Scherrer equation [70].…”

“…In addition, they could be very useful in magnetic hyperthermia therapy [22][23][24][25]. Magnetic particles modified with biodegradable PLGA or PLA were firstly prepared in the beginning of the 1990s by chemical adsorption or molecular interactions between a reactive polymer end group and the surface of the particle [26][27][28][29][30]. On the other hand, the surface modification of magnetic particles by chemical linkage of polymers is less documented, even less by the use of Ugi four component condensation (UFCC).…”

Green polyurethane synthesis by emulsion technique: a magnetic composite for oil spill removal

“…As described in previous works [9,[15][16][17][18][19][20][21][22][23][24][25] , our group is interested in the maghemite synthesis and we used similar approaches to obtain this nano material. Specifically in the present work, aqueous solutions of hydrochloric acid (2 M), ferric chloride (2 M), and sodium sulfite (1 M) were prepared.…”