Protective role of transforming growth factor-Β3 (TGF-Β3) in the formation of radiation-induced capsular contracture around a breast implant: In vivo experimental study.

Postmastectomy radiotherapy causes capsular contracture due to fibroproliferation of the capsular tissue around the implant. In fibrosis, unlike normal wound healing, structural and functional disorders are observed in the tissues caused by excessive/irregular accumulation of extracellular matrix proteins. It has been reported that transforming growth factor-ß3 (TGF-ß3) prevents and reverses fibrosis in various tissues or provides scarless healing with its antifibrotic effect. Additionally, TGF-ß3 has been shown to reduce fibrosis in radiotherapy-induced fibrosis syndrome. However, no study in the literature investigates the effects of exogenously applied TGF-ß3 on capsular contracture in aesthetic or reconstructive breast implant application. TGF-ß3, which has a very short half-life, has low bioavailability with parenteral administration. Within the scope of this study, free TGF-ß3 was loaded into the nanoparticles to increase its low bioavailability and extend its duration of action by providing controlled release. The aim of this study is to investigate the preventive/improving effects of radiation induced capsular contracture using chitosan film formulations containing TGF-ß3 loaded poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles in implant-based breast reconstruction. In the characterization studies of nanoparticles, the particle size and zeta potential of the TGF-ß3-loaded PLGA-b-PEG nanoparticle formulation selected to be used in the treatment group were found to be 123.60 ± 2.09 nm and -34.87 ± 1.42 mV, respectively. The encapsulation efficiency of the formulation was calculated as 99.91 %. A controlled release profile was obtained in in vitro release studies. Chitosan film formulations containing free TGF-ß3 or TGF-ß3-loaded PLGA-b-PEG nanoparticles were used in in vivo studies. In animal studies, rats were randomly distributed into 6 groups (n = 8) as sham, implant, implant + radiotherapy, implant + radiotherapy + chitosan film containing unloaded nanoparticles, implant + radiotherapy + chitosan film containing free TGF-ß3, implant + radiotherapy + chitosan film containing TGF-ß3 loaded nanoparticle. In all study groups, a 2 cm incision was made along the posterior axillary line at the thoracic vertebral level in rats to reach the lateral edge of the latissimus dorsi. The fascial attachment to the chest wall was then bluntly dissected to create a pocket for the implants. In the treatment groups, the wound was closed after films were placed on the outer surface of the implants. After administering prophylactic antibiotics, rats were subjected to irradiation with 10 Gy photon beams targeted to each implant site. Each implant and the surrounding excised tissue were subjected to the necessary procedures for histological (capsule thickness, cell density), immunohistochemical, and biochemical (α-SMA, vimentin, collagen type I and type III, TGF-ß1 and TGF-ß3: expression level/protein level) examinations. It was determined that the levels of TGF-ß1 and TGF-ß3 collagen type III, which decreased as a result of radiotherapy, were brought to the control level with free TGF-ß3 film and TGF-ß3 nanoparticle film formulations. Histological analyses, consistent with biochemical analyses, showed that thick collagen and fibrosis, which increased with radiotherapy, were brought to the control level with free TGF-ß3 film and TGF-ß3 nanoparticle film treatments. In biochemical analyses, the decrease in thick collagen was compatible with the decrease in the collagen type I/type III ratio in the free TGF-ß3 film and TGF-ß3 nanoparticle film groups. Changes in protein expression show that TGF-ß3 loaded nanoparticles are more successful than free TGF-ß3 in wound healing. In line with these results and the literature, it is thought that the balance of TGF-ß1 and TGF-ß3 should be maintained to ensure scarless wound healing with no capsule contracture.

Nanoparticles and Nanostructured Films with TGF-ß3: Preparation, Characterization, and Efficacy.

TGF-ß3 has been reported to have a strong therapeutic efficacy in wound healing when externally administered, but TGF-ß3's active form is rapidly metabolized and removed from the body. Therefore, a drug delivery system that can provide a new non-toxic and an effective treatment that could be locally applied and also be able to protect the stability of the protein and provide controlled release is required. The aim of the study is to prepare and characterize nanoparticles and nanostructured films with TGF-ß3 and to evaluate in vitro cytotoxicity of the loaded nanoparticles. PCL-based films containing TGF-ß3 or TGF-ß3-loaded PLGA nanoparticles were prepared with non-toxic modified solvent displacement method. The particle size and protein loading efficiency of TGF-ß3-loaded PLGA nanoparticles were 204.9 ± 10.3 nm and 42.42 ± 2.03%, respectively. In vitro release studies of TGF-ß3-loaded PLGA nanoparticle formulations revealed that the protein was completely released from the nanoparticles at the end of 24 h. In vitro release profile of film formulation containing TGF-ß3-loaded nanoparticles was similar. TGF-ß3 released from nanoparticles do not have a significant effect on proliferation of HepG2 cells demonstrating their biocompatibility. Additionally, prepared films were tested with in vivo wound healing mouse model and showed to heal significantly faster and with improved scarring. PCL films loaded with TGF-ß3 or TGF-ß3 nanoparticles prepared in this study may be an effective treatment approach for wound healing therapy after injury.

HPLC determination of olanzapine and carbamazepine in their nicotinamide cocrystals and investigation of the dissolution profiles of cocrystal tablet formulations.

Cocrystals have recently gained importance in the pharmaceutical industry. In this study, olanzapine and carbamazepine cocrystals were synthesized by using nicotinamide as cocrystal forming agent to achieve improvements in the physicochemical characteristics of the active ingredients. An HPLC method was developed to determine the amount, thus, the stoichiometric ratios of olanzapine and carbamazepine in the synthesized cocrystals. Olanzapine:nicotinamide and olanzapine tablet formulations were prepared and the developed HPLC method was applied successfully in order to compare the dissolution profiles of these formulations. An ACE 5 CN, 25 cm × 4.6 mm, 5 µm column was used and a gradient elution program was performed for simultaneous determination of olanzapine, carbamazepine and nicotinamide. Phosphate buffer (pH 5.0, 25 mM) and methanol was used in a ratio from 80:20 to 70:30 while the flow rate was 1 mL min(-1) for the elution of the compounds within 12 min. In conclusion, two different aims were achieved, the first one was to indicate the stoichiometric ratios of the active ingredients olanzapine and carbamazepine with nicotinamide in their cocrystals, and the second one was the comparison of the dissolution profiles of the olanzapine and olanzapine:nicotinamide cocrystal formulations. It was found that the cocrystal formulation with nicotinamide improved the dissolution profile of olanzapine.

The effect of inorganic salt type and concentration on hydrophilic drug loading into microspheres using the emulsion/solvent diffusion method.

AIM: In order to avoid gastric irritation caused by tolmetin sodium (TS), gastro resistant Eudragit® S 100 microsphere formulations were prepared with the emulsion/solvent diffusion method. MATERIALS: Considering the high water solubility of the TS molecule, the effects of the presence of inorganic salt (NaCl, NaBr and KH2PO4; 0.1 M and 1.0 M) in external phase and external phase pH on the encapsulation efficiency were evaluated. RESULTS: Percentage yield value was found to vary between 55.8% and 72.1%. Improvement in encapsulation efficiency was determined by increasing concentrations of NaCl, NaBr and KH2PO4. The microspheres were observed to have a spherical shape and the measured particle size values varied between 52.1 and 81.5 µm. The released amounts of the drug were found to be low as the inorganic salt concentrations increased. CONCLUSION: Conclusively, drug release in stomach pH was significantly prevented by the microspheres prepared using Eudragit® S 100 polymer, and these formulations are considered to be a model for other orally administered drugs with similar problems.

5-Fluorouracil-loaded PLA/PLGA PEG-PPG-PEG polymeric nanoparticles: formulation, in vitro characterization and cell culture studies.

In this study, 5-FU, a potent anticancer drug, is planned to be delivered via a new and promising drug delivery system, nanoparticles formed with hydrophobic core polymer and triblock copolymers; Poly(DL-lactic acid), Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymer (PLA/PEG-PPG-PEG) and Poly(D,L-lactide-co-glycolide)/Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymer (PLGA/PEG-PPG-PEG) nanoparticles. Particle size range of nanoparticles was found to be between 145 and 198 nm, which would promote the passive targeting of the nanoparticles to tumor cells based on the enhanced permeability and retention (EPR) effect. SEM images revealed all nanoparticles formulations to be spherical and without pores. Zeta potential, yield value and encapsulation efficiencies of 5-FU-loaded nanoparticles were within the range of -11.1 and -13.7 mV, 72.7-87.7% and 83.6-93.9%, respectively. Cumulative release of 5-FU was observed between 90% and 94.4% in all nanoparticle formulations by the end of 72 h, and fitness of release profiles to Higuchi model indicated matrix-controlled diffusion of the 5-FU from polymeric nanoparticles. Cell viability values of the cells treated with 5-FU-loaded nanoparticles were obtained as low as 47% and 52% with tetrazolium dye assay, suggesting that delivery of 5-FU via amphiphilic triblock copolymer nanoparticles would be a promising delivery system because of the EPR effect.

Paclitaxel-loaded lipid nanoparticles prepared by solvent injection or ultrasound emulsification.

Lipid nanoparticles were fabricated as an injectable carrier system for paclitaxel. The components for the lipid matrix were based on phospholipids, and sucrose fatty acid ester was used as an emulsifier. Formulation prepared with solvent injection has a slightly larger particle size (187.6 nm) than the formulation (147.7 nm) prepared with ultrasound emulsification. Differential scanning calorimetry results indicated that paclitaxel entrapped in the lipid nanoparticles existed in an amorphous state in the lipid matrix. In vitro drug release was rather slow; only 12.5-16.5% of the drug released from the formulations within 14 days. Lipid nanoparticles demonstrated their potential as a promising pharmaceutical formulation of paclitaxel.