encapsulation
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Mikročástice jsou předmětem intenzivního studia ve farmaceutické technologii. Důležitým parametrem při přípravě mikročástic je jejich enkapsulační účinnost. Vyšší hodnoty enkapsulační účinnosti vedou k zefektivnění výrobního procesu a následně k menší ekonomické zátěži. Cílem této studie byla příprava mikročástic metodou vnější gelace polosyntetického polymeru oxycelulosy s diklofenakem sodnou solí jako modelovým léčivem. Sledoval se vliv zvolených procesních proměnných na hodnotu enkapsulační účinnosti. Procesními proměnnými byly: teplota tvrdícího roztoku, přítomnost léčiva v tvrdícím roztoku a použití ultrazvukových vln při procesu vytvrzování. Jako optimální byla při přípravě mikročástic na bázi oxycelulosy vybrána metoda, při které se tvrdící roztok nasycený léčivem ochladil na teplotu 4 °C. Kombinace těchto parametrů vedla k nejvyšší enkapsulační účinnosti (šarže 4c – 75,24 %). Tvrzení mikročástic pomoci ultrazvukových vln se ukázalo jako nevhodné a mělo za následek snížení enkapsulační účinnosti.
Microparticles have been a subject of intensive studies in pharmaceutical technology, their encapsulation efficiency being an important parameter in the preparation of microparticles. Higher values of encapsulation efficiency result in a more effective manufacturing process and subsequently in lower economic costs. This study aimed to prepare microparticles with the use of the method of outer gelation of the semisynthetic polymer oxycellulose with diclofenac using sodium salt as the model agent and to examine the influence of selected processual variables on the value of encapsulation efficacy. Processual variables included: the temperature of the hardening solution, the presence of the active ingredient in the hardening solution and the use of ultrasound waves in the process of hardening. The method with the use of which the hardening solution saturated with the active ingredient was cooled to the temperature of 4 °C was selected as the optimal one for the preparation of microparticles on the base of oxycellulose. The combination of these parameters resulted in the highest encapsulation efficiency (batch 4c – 75.24%). Hardening of microparticles by means of ultrasound waves proved to be unsuitable and resulted in a decrease in encapsulation efficiency.
Mushrooms of the genus Ganoderma are known for diverse biological activities, demonstrated both traditionally and experimentally. Their secondary metabolites have shown cytotoxic potential across different cancer cell lines. Besides exploration of the most active components in different species or genotypes, new formulation techniques are in development. In recent years, there has been a growing interest in the use of nanomaterials because of significant potential for pharmacology applications as substance carriers. Applying nanoparticles may enhance the medicinal effect of the mushroom substances. This study investigated the cytotoxic properties of Ganoderma species methanolic extracts against the HeLa cancer cell line. Notably, the extract obtained from Ganoderma pfeifferi demonstrated the highest activity and was further used for encapsulation within synthesized mesoporous silica nanoparticles MCM-41. Subsequently, the cytotoxic effect of the loaded MCM-41 to the free form of extract was compared. The obtained results indicate successful encapsulation, and similar activity comparing encapsulated form to free extracts (IC50 16.6 μg/mL and 20.5 μg/mL, respectively). In addition, the four unique compounds were identified as applanoxidic acid A, applanoxidic acid G, ganoderone A, and ganoderone B in the G. pfeifferi. This study is an essential prerequisite for further steps like nanoparticle functionalization for sustained or on-command delivery of these natural extracts.
- Publikační typ
- časopisecké články MeSH
Cellular encapsulation associated with melanization is a crucial component of the immune response in insects, particularly against larger pathogens. The infection of a Drosophila larva by parasitoid wasps, like Leptopilina boulardi, is the most extensively studied example. In this case, the encapsulation and melanization of the parasitoid embryo is linked to the activation of plasmatocytes that attach to the surface of the parasitoid. Additionally, the differentiation of lamellocytes that encapsulate the parasitoid, along with crystal cells, is accountable for the melanization process. Encapsulation and melanization lead to the production of toxic molecules that are concentrated in the capsule around the parasitoid and, at the same time, protect the host from this toxic immune response. Thus, cellular encapsulation and melanization represent primarily a metabolic process involving the metabolism of immune cell activation and differentiation, the production of toxic radicals, but also the production of melanin and antioxidants. As such, it has significant implications for host physiology and systemic metabolism. Proper regulation of metabolism within immune cells, as well as at the level of the entire organism, is therefore essential for an efficient immune response and also impacts the health and overall fitness of the organism that survives. The purpose of this "perspective" article is to map what we know about the metabolism of this type of immune response, place it in the context of possible implications for host physiology, and highlight open questions related to the metabolism of this important insect immune response.
- MeSH
- buněčná diferenciace MeSH
- Drosophila melanogaster MeSH
- Drosophila * MeSH
- larva MeSH
- sršňovití * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Polysaccharide-based nanocomplexes, intended for simultaneous encapsulation and controlled release of 5-Fluorouracil (5-FU) and Temozolomide (TMZ) were developed via the complexation method using chitosan, alginic and polygalacturonic acid. Investigation focused on the influence of polysaccharides on the properties of the system and amelioration of the stability of the drugs, in particular TMZ. The dimensions of particles and their ζ-potential were found to range between 100 and 200nm and -25 to +40mV, respectively. Encapsulation efficiency varied from 16% to over 70%, depending on the given system. The influence of pH on the release and co-release of TMZ and 5-FU was evaluated under different pH conditions. The stability of the loaded drug, in particular TMZ, after release was evaluated and confirmed by LC-MS analysis. Results suggested that the amount of loaded drug(s) and the release rate is connected with the weight ratio of polysaccharides and the pH of the media. One-way ANOVA analysis on the obtained data revealed no interference between the drugs during the encapsulation and release process, and in particular no hydrolysis of TMZ occurred suggesting that CS-ALG and CS-PGA would represent interesting carriers for multi-drug controlled release and drugs protection.
- MeSH
- algináty chemie MeSH
- alkylační protinádorové látky chemie MeSH
- chitosan chemie MeSH
- dakarbazin analogy a deriváty chemie MeSH
- fixní kombinace léků MeSH
- fluoruracil chemie MeSH
- kyselina glukuronová chemie MeSH
- kyseliny hexuronové chemie MeSH
- léky s prodlouženým účinkem chemie MeSH
- nanočástice chemie MeSH
- nosiče léků chemie MeSH
- pektiny chemie MeSH
- prekurzory léčiv chemie MeSH
- příprava léků MeSH
- protinádorové antimetabolity chemie MeSH
- stabilita léku MeSH
- uvolňování léčiv MeSH
- Publikační typ
- časopisecké články MeSH
Chitosan and chitosan-grafted polylactic acid as a matrix for BSA encapsulation in a nanoparticle structure were prepared through a polyelectrolyte complexation method with dextran sulfate. Polylactic acid was synthetized via a polycondensation reaction using the non-metal-based initiator methanesulfonic acid and grafted to the chitosan backbone by a coupling reaction, with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide as the condensing agent. The effect of concentration of the polymer matrix utilized herein on particle diameter, ζ-potential, encapsulation efficiency, and the release kinetic of the model protein bovine serum albumin at differing pH levels was investigated. The influence of pH and ionic strength on the behavior of the nanoparticles prepared was also researched. Results showed that grafting polylactic acid to chitosan chains reduced the initial burst effect in the kinetics of BSA release from the structure of the nanoparticles. Furthermore, a rise in encapsulation efficiency of the bovine serum albumin and diminishment in nanoparticle diameter were observed due to chitosan modification. The results suggest that both polymers actually show appreciable encapsulation efficiency; and release rate of BSA. CS-g-PLA is more suitable than unmodified CS as a carrier for controlled protein delivery.
- MeSH
- chitosan chemie MeSH
- koncentrace vodíkových iontů MeSH
- kyselina mléčná chemie MeSH
- léky s prodlouženým účinkem MeSH
- molekulová hmotnost MeSH
- nanočástice chemie MeSH
- polymery chemie MeSH
- rozpustnost MeSH
- sérový albumin hovězí chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Paclitaxel (PTX) is approved for the treatment of ovarian and breast cancer. The commercially available preparation of PTX, Cremophor EL(R) is associated with hypersensitivity reactions in spite of a suitable premedication. In general, the developed liposomal PTX formulations are troubled with low PTX encapsulation capacity (maximal content, 3 mol%) and accompanied by PTX crystallisation. The application of "pocket-forming" lipids significantly increased the encapsulation capacity of PTX in the liposomes up to 10 mol%. Stable lyophilised preparation of PTX (7 mol%) encapsulated in the liposomes composed of SOPC/POPG/MOPC (molar ratio, 60:20:20) doped with 5 mol% vitamin E had the size distribution of 180-190 nm (PDI, 0.1) with zeta-potential of -31 mV. Sucrose was found to be a suitable cryoprotectant at the lipid:sugar molar ratios of 1:5-1:10. This liposomal formulation did not show any evidence of toxicity in C57BL/6 mice treated with the highest doses of PTX (100 mg/kg administered as a single dose and 150 mg/kg as a cumulative dose applied in three equivalent doses in 48-h intervals). A dose-dependent anticancer effect was found in both hollow fibre implants and syngenic B16F10 melanoma mouse tumour models.
- MeSH
- fytogenní protinádorové látky aplikace a dávkování chemie terapeutické užití toxicita MeSH
- lipidy chemie MeSH
- liposomy MeSH
- lyofilizace MeSH
- melanom experimentální farmakoterapie metabolismus MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nanotechnologie MeSH
- paclitaxel aplikace a dávkování chemie terapeutické užití toxicita MeSH
- příprava léků MeSH
- stabilita léku MeSH
- velikost částic MeSH
- viabilita buněk účinky léků MeSH
- xenogenní modely - testy protinádorové aktivity MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The bioluminescence (BLM) and colony-forming units (CFU) of Pseudomonas fluorescens HK44 were monitored during encapsulation into pre-polymerized Si(OMe)₄. The non-induced BLM of free cells was increased in the presence of 0.5-2.5 % MeOH. After mixing silica sol with the cell suspension, both BLM and CFU dropped to 1-3 and 8-18 %, respectively; both remained lowered as long as the silica biofilm contained residual MeOH. The kinetics of MeOH being released from silica biofilms (a thickness of 2-6 mm) were first-order. The decrease of bacterial activity due to encapsulation was proportional to the biofilm thickness. MeOH evolving during encapsulation is probably the principal stress factor but not the only one.
Cílem práce byla příprava mikročástic na bázi vysokomolekulárního chitosanu bez obsahu léčiva a následně příprava mikročástic s použitím 5-aminosalicylové kyseliny (5-ASA) jako modelové aktivní látky metodou vnější iontové gelace. Formulačními a procesními proměnnými byla koncentrace chitosanu a při přípravě aktivních mikročástic také přítomnost léčiva v roztoku polymeru a/nebo v použitém tvrdícím roztoku. Byl sledován vliv různých podmínek přípravy na vlastnosti mikročástic se zaměřením na zvýšení obsahu léčiva v mikročásticích. U mikročástic bez léčiva i s léčivem bylo zjištěno, že s rostoucí koncentrací chitosanu rostla jejich sféricita i jejich ekvivalentní průměr. Největší obsah léčiva byl dosažen u vzorku připraveného z 1,75% disperze chitosanu při přítomnosti léčiva v disperzi i tvrdícím roztoku. Změnou umístění léčiva během přípravy se podařilo zvýšit obsah 5-ASA maximálně 6krát (1,25% koncentrace chitosanu).
This study aimed to prepare high molecular weight chitosan blank and drug-loaded microparticles using 5-aminosalicylic acid (5-ASA) as the model active substance by an external ionic gelation. Formulation and process variables included the chitosan concentration and presence of drug in the polymer solution, and/or in hardening solution during the microparticles preparation. The effect of different preparation conditions on the properties of the microparticles was observed with a view to increase drug content in microparticles. For both types of microparticles (with and without the drug), it was found that their sphericity and equivalent diameter increased with increasing chitosan concentration. The drug content of drug-loaded microparticles was the highest in the case of the sample prepared from 1.75% chitosan dispersion, when the drug was present both in the chitosan dispersion and the hardening solution. Maximum six times higher drug content was achieved by change of the placement of 5-ASA during preparation (1.25% chitosan concentration).
- Klíčová slova
- mikročástice, enkapsulační účinnost, vnější iontová gelace, stereoskopická mikroskopie,
- MeSH
- chitosan * MeSH
- farmaceutická technologie * metody MeSH
- mesalamin * MeSH
- mikroskopie MeSH
- nosiče léků * MeSH
- polymery MeSH
- povrchové vlastnosti MeSH
- rozpustnost MeSH
- velikost částic * MeSH
- viskozita MeSH
