Nanomedicine, the nanotechnology for the development of effective and safe medicines, has influenced biotechnology and chemistry during several decades.1,2 The interest in nanomedicine offers the innovation of drug delivery system using nanoparticles.3 The advantages of nanoparticles in the therapeutic application include the following properties in. Over the past 30 years, there have been a number of nanoparticle models that have been developed for therapeutic purposes.
Nanoparticles for Cancer Therapy
Doxorubicin-encapsulated liposomes (DOXIL) have already been approved by the FDA for nanomedicine.10 Genoxol-PM11, the polymeric nanoparticle including paclitaxel which is also already used for therapeutic purposes. However, the number of nanoparticles in clinical development is too small compared to the number of researches in nanomedicine.
Polymeric Nanoparticles
Active Targeted Nanoparticles
Mitochondrial Drug Delivery System
Synthesis of PEO-b-PLA Block Copolymer for Controlling Encapsulation Stability
Research Objectives
The PEO-b-PLA polymers in nano-precipitation lead to nanoparticles that encapsulated hydrophobic drugs while maintaining the stability of hydrophilic PEO shell. The manufacturing process is shown in the following section. The molar ratio between two blocks was determined by integrating the polyethylene glycol unit and the proton in the poly(lactic acid) found to be 133:54. The calculation based on proton NMR data gives the result when 3.89 kD PLA was added to PEO (5 kD) units. The molar ratio between two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the proton in the poly(lactic acid) found to be 133:103.
The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the proton in the poly(lactic acid), which was found to be 133:389. The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the proton in poly(lactic acid), which was found to be 227 : 74. The molar ratio between the two blocks was determined by integrating the methoxy proton in the unit of polyethylene glycol and proton in poly(lactic acid), which was found to be 227 : 91.
The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the proton in the poly(lactic acid) which was found to be 214:395. The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and proton in poly(lactic acid) was found to be 454 : 138. The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the proton in poly(lactic acid) was found to be 454 : 384.
The degree of ligand conjugation was identified by UV spectroscopy by checking the peak of pyridathione in the filtered solution. In this study, we probed the pyridothione peak in the UV to determine ligand conjugation.
Materials and Methods
Results and Discussion
The calculation based on proton NMR data gives the result when 7.41 kD PLA was added to PEO (5 kD) units. The calculation based on proton NMR data gives the result when 28.05 kD PLA was added to PEO (5 kD) units. The calculation based on proton NMR data gives the result when 5.33 kD PLA was added to PEO (10 kD) units.
The calculation based on proton NMR data gives the result when 6.55 kD PLA was added to PEO units (10 kD). The calculation based on proton NMR data gives the result as 28.44 kD PLA was added to PEO units (10 kD). The calculation based on proton NMR data gives the result as 9.94 kD PLA was added to PEO units (20 kD).
The calculation based on proton NMR data gives the result as 27.65 kD PLA added to PEO (20 kD) units. In the 5K-4K and 5K-7K systems, the diameter of DiO-encapsulated micelle is smaller than that of control micelle. We hypothesized that the longer PLA chain cannot form a stable hydrophobic core in the micelle system.
Conclusion and Future Work
Introduction & Background
Research Objectives
At first, two dye molecules with FRET pairs, DiO and DiI (FRET donor and acceptor) were independently encapsulated in the supramolecular nanogels. From this approach, improved specificity and increased quantity of drug molecules provide the method of influencing drug delivery system research. The pyridyldisulfide (PDS) units in the random copolymer enable the creation of the disulfide group through the exchange reaction of the thiol with the cysteine in the Z domain.
Finally, the disulfide groups in the crosslinkers can be cleaved by means of thiol-disulfide exchange reactions. Furthermore, the cysteine in the Z domain makes this reaction under contact with our nanogel system. The ligand molecule was composed of hydrophilic ethylene glycol moiety for biodegradability and flexibility in the biological environment.
In the case of model drug encapsulation, as is a well-known method, the dye molecules were dissolved in an organic solvent and then dropped into the polymer solution in the hydrogel state. The concentration of the polymer in the solution was 0.1 mg/mL. DiO-encapsulated Nanogel + DTT 20 mol%. In this system, if the DiO molecule was not encapsulated in the core of the nanogel but intercalated with the polymer molecule, it results in the inhibition of the thiol exchange reaction between the nanogel surface and the target ligand molecule.
Materials and Methods
Results and Discussion
We prepared supramolecular nanogels by electrostatic interaction between negative natural polypeptide (gelatin B) and a positive small surfactant (CTAB and synthetic peptide amphiphiles). 3,3′-dioctadecyloxacarbocyanine perchlorate (DiO) and 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl-indocarbocyanine perchlorate (DiI) encapsulated in (a) CTAB micelles, (b) NG1-CTAB, and (c) NG2-CTAB. This indicates that the electrostatic interaction between negative gelatin polymer and positive surfactant micelles can be weakened by serum proteins through competitive interaction causing disassembly of the nanogel system.
As shown in Figure 3.4b, the modified gelatin interacts strongly with positive micelles, forming highly stable supramolecular nanogels. Result of size distribution and FRET evolutions of the NG2-CTAB system. a) FRET evolutions within NG2-CTAB with 10% fetal bovine serum (FBS) in tris(hydroxymethyl)aminomethane (Tris) buffer solution at pH 7.4. To prove this system, we investigated the release of hydrophobic charge from NG2-CTAB-Suc with and without treatment of MMP 9. Figure 3.5).
First, we encapsulated doxorubicin as a cargo drug in supramolecular nanogels and then measured cell viability with MMPs activity. The difference in toxicity from the addition of MMP inhibitor showed that the supramolecular nanogel system has sensitivity to MMPs. Color release from NG2-CTAB-Suc (0.65 mg/ml) at different time points after incubation (a) with and (b) without active matrix metalloproteinase-9 (MMP-9).
Conclusions
Affinity Protein-Conjugated nanogel system
- Research Objectives
- Materials and Methods
- Results and Discussion
- Conclusions
Specificity of the Fc region of the GST-Z domain as confirmed by quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and in vitro confocal imaging. Finally, the easy degree of conjugation between the ligand and the drug carrier has a great advantage in application. The mixture was purified with cold ether. The molar ratio between the two blocks was determined by integrating the methoxy proton in the polyethylene glycol unit and the aromatic proton in the pyridine and found to be 67%:33% (PEO:PDSEMA).
The mixed organic solvents are mixed dropwise into an aqueous phase under stirring.61 When the organic phase comes into contact with the water, the hydrophobic components in the organic solutions are precipitated and then self-assembly takes place in a core-shell-like structure for the reduction of the free energy.62 After self-assembly, the organic solvent kept under atmospheric pressure for evaporation. In the middle of this nanoprecipitation method, the hydrophobic drug molecule is trapped in the core of the nanoparticle, surrounded by hydrophilic PEGylated shell for stabilization in aqueous environment. Then, we treated GSH solution for the Dox-NG with different concentrations to track the degree of release of cargo from Dox-NG system.
The intensity of the excitation signal of doxorubicin (545 nm) was used for the calculation of relative release. GST-Z/Ab domain as targeting ligand was treated on DOX-NG by a simple mixing method. Third, it possesses thiol group which enables it to perform disulfide cross-linking in the light state.
Mitochondria Targeting Nanogel System for Drug Delivery
Research Objectives
To develop this new type of delivery vehicle, we introduce a mitochondrial targeting ligand molecule into a self-crosslinked nanogel. It has functional pyridyl disulfide groups on its surface, which facilitates ligand conjugation by thiol exchange reaction, forming a disulfide group. Moreover, the other end of the thiol group will react with the drug carrier for surface modification.
Our strategy for the actualization of mitochondrial targeting nanoparticles is to start with the encapsulation of model drug molecule with self-crosslinked nanogel. Then, thiolated mitochondrial targeting ligand molecule will be modified on the surface of nanogel by means of thiol exchange reaction.
Materials and Methods
DCM was added as solvent and then ground potassium hydroxide (7.945 g, 141.6 mmol) was added with stirring. Acetonitrile was added to the reaction mixture and then sonication was performed to dissolve KI. The signal of pyridothion at 343 nm indicates that the cross-linking via DTT was carried out on the nanogel surface via a thiol exchange reaction.
The effect of sodium methoxide on the nanogel was minimized by removing the sodium methoxide salt from the reaction mixture. The thiol-modified ligand was added to the dye-encapsulated nanogel and then stirred for 12 h to modify the surface. The increased pyridathione signal at 343 nm indicates that the ligand conjugation was carried out via a thiol exchange reaction.
As shown in Figure 5.7, the cross-linking of nanogel and surface modification with thiol-modified targeting ligand was well performed. The effect of DTT treatment will require further research. a) Nanogel solution (b) DiO encapsulated nanogel. 20 mol% of the DTT-treated nanogels were incubated with Hela cells at a concentration of 20 μg/ml for 4 h. a) DiI encapsulated nanogel with mitochondria-targeting ligand; (b) mitotracker signal;
Results and Discussion
Conclusions and Future Work
The ethylene glycol moiety was expected to show high flexibility with biocompatibility in the biological environment. The thiol group in the ligand molecule performed thiol exchange on the surface of self-crosslinked nanogel. The amount of DTT for cross-linking nanogel may also be the other reason for this phenomenon.
Through this result, we planned detail experiments to get more clear evidence by adjusting the concentration of nanogel solution. Further investigation with drug molecule and efficacy will be explored as future work with in vivo experiments. Matsumoto, S.; Miyata, Y.; Ohkura, H.; Kin, K.; Babies.; Yama, T.; Kannami, A.; Takamatsu, Y.; It OK.; Takahashi, K., Phase I and pharmacokinetic study of MCC-465, a doxorubicin (DXR) encapsulated in PEG-immunoliposome, in patients with metastatic gastric cancer.
T.; Papahadjopoulos, D., Antibody targeting of liposomes - Cell specificity obtained by conjugation of F(Ab')2 to the vesicle surface. R.; Mahdipoor, P.; Lavasanifar, A., A novel use of an in vitro method to predict the in vivo stability of block copolymer-based nano-containers. Uhlen, M.; Guss, B.; Nilsson, B.; Gatenbeck, S.; Philipson, L.; Lindberg, M., Complete sequence of the staphylococcal gene encoding protein-a - a gene evolved through multiple duplications.
Synthesis of PEO-b-PLA block copolymer for controlling encapsulation stability
GST-Z conjugated nanogels for customizing theragnosis
S. Food and Drug Administration (FDA)
N′,N′-Tetramethyl-O-(1H-benzotriazol-1-yl)uronium hexafluorophosphate (HBTU)
N –Diisopropylethylamine (DIPEA)
N -dimethyl formamide (DMF)
