scholarly journals Development of sonosensitive Poly-(L)-lactic acid nanoparticles

2017 ◽  
Vol 3 (2) ◽  
pp. 679-682 ◽  
Author(s):  
Pia-Theresa Hiltl ◽  
Michael Fink ◽  
Stefan J. Rupitsch ◽  
Geoffrey Lee ◽  
Helmut Ermert
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Acoustic Pressure ◽  
Region Of Interest ◽  
Ultrasound Wave ◽  
Chemotherapeutic Drugs ◽  
Epr Effect ◽  
Inertial Cavitation ◽  
Treatment Techniques ◽  
Freeze Dried

AbstractDue to serious side effects of traditional chemotherapeutic treatment, novel treatment techniques like targeted drug delivery, which allows a reduction of the overall dosage of drugs, are investigated. It is worth mentioning that at the same time, precise drug delivery offers an increased dosage of chemotherapeutic drugs in the tumorous area employing the EPR effect. Therefore, vehicles smaller than 400 nm can be used to pass the poorly aligned endothelial cells of tumour vessels passively through their fenestrations. In a subsequent step, the chemotherapeutic drugs need to be released. One possibility is an ultrasound-based release via inertial cavitation. Thereby, it is desirable to restrict the drug release to a narrow range. Thus, the cavitation inducing ultrasound wave has to be focused to that region of interest. Ultrasound frequencies of more than 500 kHz enable sufficient focusing, however, inertial cavitation occurs primarily at much lower frequencies. In order to afford inertial cavitation at 500 kHz, either bigger particles in the range of micrometres are needed as cavitation nucleus, which is not possible due to the EPR effect or high acoustic pressure is needed to generate inertial cavitation. Nevertheless, this high pressure is inappropriate for clinical applications due to thermal and mechanical effects on biological tissue.We have produced Poly-(L)-lactic acid (PLLA) nanoparticles by a solvent evaporation technique that serve as nucleus for inertial cavitation at moderate acoustic pressure of 800 kPa and at high frequencies of 800 kHz after the particles have been freeze-dried. In this contribution, we characterize the designed particles and present the production process. Moreover, we show that these particles enable inertial cavitation at an acoustic pressure and at acoustic frequencies which are commonly used in clinical ultrasound units. We also show that other particles with the same size at the same acoustic parameters do not induce cavitation activity.

scholarly journals Determination of the Cavitation Pressure Threshold in Focused Ultrasound Wave Fields applied to Sonosensitive, Biocompatible Nanoparticles for Drug Delivery Applications

2020 ◽  
Vol 6 (3) ◽  
pp. 539-542
Author(s):  
Benedikt George ◽  
Markus Lehner ◽  
Michael Fink ◽  
Stefan J. Rupitsch ◽  
Helmut Ermert ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Focused Ultrasound ◽  
Ultrasound Wave ◽  
Pharmaceutical Ingredients ◽  
Inertial Cavitation ◽  
Biocompatible Nanoparticles ◽  
Pressure Threshold ◽  
Cavitation Pressure

AbstractEmploying sonosensitive nanoparticles as carriers of active pharmaceutical ingredients emerges in ultrasonic Drug Delivery. Drug release can be initiated by focused ultrasound via the effect of inertial cavitation in certain target areas of particle loaded tissue. For stimulating inertial cavitation, a specific peak rarefaction pressure threshold must be exceeded. This pressure threshold has to be determined in order to estimate the risk of tissue damage during the drug release procedure. Therefore, this study provides a method to reliably verify the cavitation pressure threshold of sonosensitive and biocompatible nanoparticles.

In Vivo Characteristics of Injectable Poly(DL-Lactic Acid) Microspheres for Long-Acting Drug Delivery

1998 ◽  
Vol 24 (9) ◽  
pp. 819-825 ◽  
Author(s):  
Daishiro Kobayashi ◽  
Satoru Tsubuku ◽  
Hidetoshi Yamanaka ◽  
Masaharu Asano ◽  
Masaharu Miyajima ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Long Acting

scholarly journals Stereocomplex Polylactide for Drug Delivery and Biomedical Applications: A Review

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2846
Author(s):  
Seung Hyuk Im ◽  
Dam Hyeok Im ◽  
Su Jeong Park ◽  
Justin Jihong Chung ◽  
Youngmee Jung ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Drug Carrier ◽  
Micelle Formation ◽  
Weak Stability ◽  
Critical Fields ◽  
Physical Strength ◽  
Anti Cancer

Polylactide (PLA) is among the most common biodegradable polymers, with applications in various fields, such as renewable and biomedical industries. PLA features poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) enantiomers, which form stereocomplex crystals through racemic blending. PLA emerged as a promising material owing to its sustainable, eco-friendly, and fully biodegradable properties. Nevertheless, PLA still has a low applicability for drug delivery as a carrier and scaffold. Stereocomplex PLA (sc-PLA) exhibits substantially improved mechanical and physical strength compared to the homopolymer, overcoming these limitations. Recently, numerous studies have reported the use of sc-PLA as a drug carrier through encapsulation of various drugs, proteins, and secondary molecules by various processes including micelle formation, self-assembly, emulsion, and inkjet printing. However, concerns such as low loading capacity, weak stability of hydrophilic contents, and non-sustainable release behavior remain. This review focuses on various strategies to overcome the current challenges of sc-PLA in drug delivery systems and biomedical applications in three critical fields, namely anti-cancer therapy, tissue engineering, and anti-microbial activity. Furthermore, the excellent potential of sc-PLA as a next-generation polymeric material is discussed.

Glass transition behavior of carnosine and its impact as a protectant on freeze-dried lactic acid bacteria

2021 ◽  
Author(s):  
Shuto Mikajiri ◽  
Tomochika Sogabe ◽  
Ruodan Cao ◽  
Takahiro Kikawada ◽  
Toru Suzuki ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Lactic Acid Bacteria ◽  
Transition Behavior ◽  
Freeze Dried

Polymeric micelles as drug delivery systems in cancer: challenges and opportunities

Nanomedicine ◽  
2021 ◽  
Author(s):  
Swati Biswas
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Polymeric Micelles ◽  
Delivery Systems ◽  
Clinical Translation ◽  
Current Status ◽  
Chemotherapeutic Drugs ◽  
Challenges And Opportunities

Tweetable abstract Micelles are nanocarriers for hydrophobic chemotherapeutic drugs. This editorial discusses the current status of preclinical micellar research and sheds light on the possibility of their clinical translation.

scholarly journals Effect of Film Formation Method and Annealing on Crystallinity of Poly(L-Lactic Acid) Films

2011 ◽  
Author(s):  
Shan-Ting Hsu ◽  
Y. Lawrence Yao
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Film Formation ◽  
Solvent Casting ◽  
Crystalline Morphology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lamellar Structures ◽  
Coating Methods ◽  
Formation Method

Poly(L-lactic acid) (PLLA) has been shown to have potential medical usage such as in drug delivery because it can degrade into bioabsorbable products in physiological environments, and its degradation is affected by crystallinity. In this paper, the effect of film formation method and annealing on the crystallinity of PLLA are investigated. The films are made through solvent casting and spin coating methods, and subsequent annealing is conducted. The resulting crystalline morphology, structure, conformation, and intermolecular interaction are examined using optical microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. It is observed that solvent casting produces category 1 spherulites while annealed spin coated films leads to spherulites of category 2. Distinct lamellar structures and intermolecular interactions in the two kinds of films have been shown. The results enable better understanding of the crystallinity in PLLA, which is essential for its drug delivery application.

The Evolution of Tumor-Targeted Drug Delivery: From the EPR Effect to Nanoswimmers

2013 ◽  
pp. n/a-n/a
Author(s):  
Nour Zoabi ◽  
Adi Golani-Armon ◽  
Assaf Zinger ◽  
Maayan Reshef ◽  
Zvi Yaari ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Drug Delivery ◽  
Epr Effect ◽  
Targeted Drug

scholarly journals Viability of lactic acid bacteria in different components of Ogi with anti diarrhoeagenic E. coli activities

2019 ◽  
Vol 3 (6) ◽  
pp. 206-213
Author(s):  
Roseline Eleojo Kwasi ◽  
Iyanuoluwa Gladys Aremu ◽  
Qudus Olamide Dosunmu ◽  
Funmilola A. Ayeni
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antimicrobial Properties ◽  
Culture Method ◽  
Antimicrobial Activities ◽  
Drying Methods ◽  
Bacterial Strains ◽  
E Coli ◽  
Log Reduction ◽  
Freeze Dried

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.

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