Nanocapsules by Miniemulsion Polymerization with Biodegradable Surfactant and Hydrophobe

Romio, Ana Paula; Sayer, Cláudia; Araújo, Pedro Henrique Hermes de; Al-Haydari, Mariam; Wu, Libo; Rocha, Sandro R. P. da

doi:10.1002/macp.200800593

Cited by 29 publications

(29 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The presence of "flattened" microspheres seen in Figure 2.21a may indicate that some PCL microspheres being hollow, demonstrating the same sunken shape of hollow spheres reported in the literature [110][111][112]. In nanoparticle mini-emulsions, these hollow spheres arise from phase separation inside the particles between the hydrophobic material and polymer [110,113]. Since these "hollow" spheres are minimally present, these microspheres are still considered an acceptable product.…”

Section: Discussionsupporting

confidence: 60%

Drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy

Floyd

Galperin

Ratner

2015

J Biomedical Materials Res

View full text Add to dashboard Cite

Departments of Bioengineering and Chemical EngineeringThe grim prognosis for patients diagnosed with malignant gliomas necessitates the development of new therapeutic strategies for localized and sustained drug delivery to combat tumor drug resistance and regrowth. Here we introduced the novel formulation of drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy (DREAM BIG Therapy) that is applied post-resection. DREAM BIG Therapy consists of three types of microspheres [poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA), and poly(ε-caprolactone) (PCL)] containing various encapsulated chemotherapeutics, suspended in a degradable, aqueous poly(Nisopropylacrylamide) (PNIPAM) solution. The thermoresponsive PNIPAM solution is capable of suspending drug encapsulated microspheres at room temperature which can be "sprayed on" the post-surgical site. The physiological temperature of the treatment site (37°C) would cause PNIPAM solution to solidify and form an adherent gel layer with entrapped microspheres, providing intimate contact with remaining tumor cells. Over time, PLGA (rapid degradation), PLA (medium speed degradation), and then PCL (slow degradation) microspheres would break iv down, releasing their drug payloads in a sequential, multi-drug release directly to the tumor site, addressing cancerous regrowth and tumor drug resistance. This dissertation will address the development of DREAM BIG Therapy, from microsphere formulation to pilot in vivo studies.Initial work focused on developing blank and drug encapsulated microspheres using emulsion techniques. Preliminary studies utilized rhodamine B as a model drug for encapsulation in PLGA, PLA, and PCL particles and optimized formulation parameters to achieve a high encapsulation. Then, gefitinib, IgG, and lomustine were encapsulated in PLGA, PLA, and PCL microspheres, respectively, achieving encapsulation efficiencies greater than 80% and drug loadings greater than 0.3%. The in vitro release of gefitinib and IgG were also studied. Gefitinib released from PLGA microspheres over 40 days while the release of IgG from PLA microspheres was slower, over a year long period.The microsphere-PNIPAM system was tested for aerosolized application ex vivo. The aqueous PNIPAM solution suspended the microspheres and was aerosolized before phase transitioning to an adherent gel layer on the tissue, entrapping the microspheres on the tissue surface. Finally, when tested in vivo, the gefitinib encapsulated PLGA microspheres entrapped in PNIPAM slowed the tumor volume growth of a subcutaneous C6 glioma in comparison to blank PLGA microspheres entrapped in PNIPAM. Overall, this research confirms the potential of DREAM BIG therapy for future use with multiple chemotherapeutics and microsphere types to combat gliomas at a localized site.v

show abstract

Section: Discussionsupporting

confidence: 60%

Drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy

Floyd

Galperin

Ratner

2015

J Biomedical Materials Res

View full text Add to dashboard Cite

show abstract

“…The high co-stabilizer/polymer (HD/PHBV) ratio, 4/3 and 4/5 (wt/wt) for, respectively, 3 and 5 wt% of PHBV, led to phase separation inside the polymer particles during solvent evaporation, resulting in the formation of nanocapsules (a core-shell morphology with a liquid HD core and a PHBV shell [Romio et al, 2009a;Romio et al, 2009b]). This can be observed for the larger particles that appear as hollow capsules in the FEG-SEM images of nanoparticles produced with 5 wt% of HPHBV in Figure 2(b).…”

Section: Effect Of Phbv Molar Massmentioning

confidence: 99%

Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) nanoparticles prepared by a miniemulsion/solvent evaporation technique: effect of phbv molar mass and concentration

Leimann

Cardozo‐Filho

Sayer

et al. 2013

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

-Miniemulsification and emulsion/solvent evaporation techniques were combined to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles. Those nanoparticles were prepared with different PHBV molar masses and PHBV concentrations to verify their effect on the final particle size. Nanoparticles with an average diameter of 133 nm were obtained when a low molar mass (Mw = 44,350 g/mol) polymer was used. On the other hand, when high molar mass PHBV (Mw = 369,900 g/mol) was used under the same operational conditions, nanoparticles with a 300 nm average diameter and a broader particle size distribution were formed. Results also showed that increasing the PHBV concentration led to an increase of the particle size and, when the polymer/costabilizer (PHBV/hexadecane) weight ratio was close to 1, nanocapsules (hexadecane core surrounded by a PHBV shell) were formed.

show abstract

“…Therefore, the use of biocompatible polymers and solvent-free, natural, and nonionic emulsifiers such as lecithin, in addition of costabilizers based in oils and fatty acids, is preferred for biomedical applications [9,[23][24][25][26].…”

Section: International Journal Of Polymer Sciencementioning

confidence: 99%

“…PMMA nanoparticles were produced by the miniemulsion polymerization technique and the formulations were defined according to previous studies conducted in the research group in the synthesis of biocompatible nanoparticles for drug delivery [23][24][25][26]. Formulations used in particles synthesis are presented in Table 1 for nanospheres (NS) and nanocapsules (NC).…”

Section: Pmma Nanoparticles Synthesis For Progesterone En-mentioning

confidence: 99%

Method Validation for Progesterone Determination in Poly(methyl methacrylate) Nanoparticles Synthesized via Miniemulsion Polymerization

Fogolari

Felippe

Leimann

et al. 2017

International Journal of Polymer Science

Self Cite

View full text Add to dashboard Cite

Exogenous progesterone has several applications in human health and in veterinary medicine, especially in fixed-time artificial insemination protocol. Progesterone nanoencapsulation in biocompatible polymers, such as poly(methyl methacrylate) (PMMA), is an alternative to substitute silicone-based release device traditionally used for estrus control. Progesterone concentration inside the nanoparticles must be precisely known; for that reason, a validation methodology must be applied to ensure reliable results, suitable for nanoparticles application. In this work, an UV-Vis spectrophotometric method was validated for the determination of progesterone in PMMA nanoparticles synthesized by miniemulsion polymerization. Chloroform was used as solvent, showing selectivity to the encapsulated drug and the components of the polymeric matrix did not influence progesterone recovery. Detection and quantitation limits (DL and QL) obtained were 0.32 and 0.96 mg⋅L −1 , respectively, and precision tests (between different analysts and equipment) indicated acceptable Relative Standard Deviations (RSD < 5%). Miniemulsion polymerization reactions were carried out producing two different morphologies: nanospheres (NS) and nanocapsules (NC), with average intensity diameters (Dz) of 150-200 nm and 240-300 nm, respectively. Polymerization gravimetric conversions obtained for both cases were higher than 95% and encapsulation efficiencies greater than 69% and 90% for the nanospheres and nanocapsules, respectively.

show abstract

Nanocapsules by Miniemulsion Polymerization with Biodegradable Surfactant and Hydrophobe

Cited by 29 publications

References 35 publications

Drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy

Drug encapsulated aerosolized microspheres as a biodegradable, intelligent glioma therapy

Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) nanoparticles prepared by a miniemulsion/solvent evaporation technique: effect of phbv molar mass and concentration

Method Validation for Progesterone Determination in Poly(methyl methacrylate) Nanoparticles Synthesized via Miniemulsion Polymerization

Contact Info

Product

Resources

About