Two cases of granuloma mimicking local recurrence after pulmonary segmentectomy.

BACKGROUND: Fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT is the most sensitive non-invasive imaging method for the detection of tumor metastasis and recurrence, but sometimes reveals false-positive results. Herein, we report two cases of false-positive results on PET/CT scans along with elevated serum carcinoembryonic antigen (CEA) levels, mimicking local recurrence after pulmonary segmentectomy. CASE PRESENTATION: Case 1; A 75-year-old woman underwent thoracoscopic left basal segmentectomy for primary lung cancer. Follow-up at 6 months after the surgery revealed serum CEA level elevation and chest CT showed a nodule measuring 25 × 22 mm in the residual left lower lobe. PET/CT revealed FDG uptake in the nodule diagnosed as local recurrence of lung cancer, and the patient underwent partial resection of the nodule. Microscopic examination of the resected specimen revealed granuloma caused by polyglycolic acid (PGA) sheet. Case 2; A 58-year-old man underwent VATS right S1 segmentectomy for lung metastasis from rectal carcinoma. Serum CEA levels gradually increased after surgery, and PET/CT revealed FDG uptake in the stump diagnosed as local recurrence of the lung metastasis. The patient underwent completion lobectomy 6 months after the segmentectomy, and the pathology of the resected specimen revealed an inflammatory granuloma caused by PGA suture. CONCLUSIONS: Although suture and stapler granulomas have been reported, granuloma caused by PGA sheets has never been reported. Postoperative recurrence of lung cancer should be diagnosed with not only PET/CT scans and serum tumor markers but also pathological findings, to avoid unnecessary treatment such as chemotherapy, radiation, and difficult reoperation.

A two-cohort feasibility study on polyglycolic acid yarn implantation for abolition of saphenous vein reflux.

OBJECTIVE: The objective of this study was to evaluate the feasibility and safety of a polyglycolic acid (PGA) yarn implant for nonthermal ablation of saphenous vein reflux. METHODS: In two consecutive cohort studies (TAHOE I and TAHOE II), the feasibility of abolition of great saphenous vein (GSV) reflux by implantation of a PGA yarn was tested under ultrasound guidance in 51 and 30 patients, respectively. The use of tumescent local anesthesia was not required. Graduated compression stockings and thrombosis prophylaxis with low-molecular-weight heparin were used for 2 weeks after intervention in the first study only. RESULTS: Of 81 enrolled patients, 77 (95%) were available at 6-month follow-up. Complete occlusion of the treated GSV was confirmed by duplex ultrasound in all patients except one patient at day 1. In TAHOE II, closure was preserved in a higher percentage of patients at 6 weeks, with 96.4% vs 82.0% in TAHOE I. The 6-month Kaplan-Meier estimated occlusion rates for TAHOE I and TAHOE II were 68% (95% confidence interval [CI], 54%-79%) and 69% (95% CI, 49%-82%), respectively, with an estimated combined occlusion rate of 69% (95% CI, 57%-76%). Kaplan-Meier analysis yielded a combined reflux-free rate of 85% (95% CI, 75%-91%) at 3 months of follow-up and a rate of 81% (95% CI, 71%-88%) at 6 months of follow-up. Venous Clinical Severity Score (VCSS) improved from a combined mean of 4.6 ± 3.1 at baseline to 2.1 ± 2.2 and 1.6 ± 1.9 at 3 and 6 months, respectively (P < .0001 for 3- and 6-month results). In TAHOE II, four patients with venous ulcers healed at an average of 1.3 months after treatment. CONCLUSIONS: First-in-human use of an endovenous PGA yarn implant for occlusion of refluxing GSVs proved to be feasible, with no serious adverse events. However, recanalization was observed during a period of 6 months in 31% of patients.

Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity.

Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide), (PLGA), and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate) (PLGA/PHB). The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

Longer survival of a patient with glioblastoma resected with 5-aminolevulinic acid (5-ALA)-guided surgery and foreign body reaction to polyglycolic acid (PGA) suture.

In recent years, there is a growing evidence that using 5-aminolevulinic acid (5-ALA)-guided resection of a cerebral glioblastoma, associated with chemoradiotherapy determine a prolonged survival of these patients, even though this period do not exceed 15 months. 5-ALA is a natural biochemical precursor of heme that is metabolized to fluorescent porphyrins, particularly protoporphyrin IX (PPIX) and no foreign reaction were noted until now. However, foreign body reaction developing in neurosurgery is documented in a few number of cases to suture material, surgical hemostatic material, or surgical glove starch, but up to now we could not find any article about granulomatous inflammation to polyglycolic acid (PGA) suture after brain tumor resection. Here we present a case of a delayed foreign body granuloma to PGA suture diagnosed after 10 months following fluorescence-guided surgery with 5-ALA for resection of a cerebral glioblastoma that was difficult to diagnosis both clinically and on magnetic resonance imaging (MRI). Moreover, the survival time was longer. We correlate the appearance of foreign body granuloma with the patient's persistent pre- and postoperative lymphocytosis. We also suggest that the chronic inflammation inhibited the proliferation of any tumoral cells which could remain in the tumor bed because we did not noticed on serial MRI scans a rapidly tumor growth during the first 10 months after the initial surgery as we have expected to be for a glioblastoma.

Cartilage suspension using a poly (lactic-co-glycolic) acid system.

BACKGROUND: This study aims to determine whether a bar-like implant made of poly lactic-co-glycolic acid (PLGA) could be used for cartilage suspension and whether the implant would be suitable for rhinoplasty. METHODS: Three types of in vivo animal experiments were performed. First, the ear cartilage was incised in a full-thickness pattern, and the PLGA system was placed between the upper and lower cartilage to offer support to the tissue. Second, after the ear cartilage was forcibly bent, an implant was placed in the cartilage. For these rabbits, the outer aspect of the ear cartilage was assessed at 2, 4, 8, 10, and 12 weeks postoperatively. In addition, tissue samples were collected for histological evaluation 12 weeks after surgery. Third, the bar-like nasal implant was used for nasal septal suspension. We obtained micro-computed tomography (CT) images and evaluated the inflammatory reaction at 12 weeks postoperatively. RESULTS: The results of both the ear suspension and bending retention tests revealed that the characteristic shapes of the cartilage were well preserved at 12 weeks postoperatively. Moreover, no abnormal inflammatory reaction was present in any site in the experimental group. We successfully implanted the bar-like nasal implant in the rabbit's septum, and no complications occurred. Furthermore, the physical examination and the micro-CT images did not reveal any nasal obstruction or inflammation. CONCLUSIONS: We confirmed that an implant made of PLGA can be maintained in the cartilage tissue and believe that this can be applied in rhinoplasty as an alternative to autologous cartilage.

Evaluation of polyesteramide (PEA) and polyester (PLGA) microspheres as intravitreal drug delivery systems in albino rats.

PURPOSE: To study the suitability of injectable microspheres based on poly(ester amide) (PEA) or poly lactic-co-glycolic acid (PLGA) as potential vehicles for intravitreal drug delivery in rat eyes. Dexamethasone-loaded PEA microspheres (PEA + DEX) were also evaluated. METHODS: Forty male Sprague Dawley rats were divided into four groups that received different intravitreally injected microspheres: PEA group (n = 12); PLGA group (n = 12); PEA + DEX group (n = 8); and control group (no injection, n = 8). Electroretinography (ERG), fundus autofluorescence (FAF), and spectral domain optical coherence tomography (sdOCT) were performed at baseline, weeks 1 and 2, and months 1, 2, and 3 after intravitreal injection. Eyes were histologically examined using light microscopy and transmission electron microscopy at the end of the in vivo study. RESULTS: There were no statistically significant changes in ERG among the groups. Abnormal FAF pattern and abnormal deposits in OCT were observed after injection but almost completely disappeared between week 2 and month 3 in all injected groups. GFAP staining showed that Müller glia cell activation was most pronounced in PLGA-injected eyes. Increased cell death was not observed by TUNEL staining at month 1. In electron microscopy at month 3, the remnants of microparticles were found in the retinal cells of all injected groups, and loss of plasma membrane was seen in the PLGA group. CONCLUSIONS: Although morphological changes such as mild glial activation and material remnants were observed histologically 1 month and 3 months after injection in all injected groups, minor cell damage was noted only in the PLGA group at 3 months after injection. No evidence of functional abnormality relative to untreated eyes could be detected by ERG 3 months after injection in all groups. Changes observed in in vivo imaging such as OCT and FAF disappeared after 3 months in almost all cases.

Design and evaluation of antibiotic releasing self- assembled scaffolds at room temperature using biodegradable polymer particles.

Biodegradable polymer-based drug-eluting implants offer many advantages such as predictable drug release kinetics, safety, and acceptable drug loading under ambient conditions. Herein, we describe fabrication and evaluation of antibiotic loaded scaffolds for localized delivery and tissue engineering applications. PDLLA particles entrapping gentamycin were formulated using solvent evaporation method and used for scaffold fabrication. Optimization of formulation parameters such as pH of the internal aqueous phase and combination of excipients like glycerol, polyvinyl alcohol (PVA) resulted in high entrapment efficiencies up to 96% of gentamicin in particles with drug load of 16-18µg/mg of polymer particles. These microparticles were fused in presence of methanol at ambient temperatures to form scaffolds of different geometry having reasonable mechanical strength. Porosity of these scaffolds was found to be more than 80%. Antibiotic released from the scaffolds was found to be bioactive as tested against Staphylococcus aureus and the release pattern was biphasic over a period of one week. The scaffolds were found to be non-toxic to murine fibroblasts cultures in vitro as well as to mice upon subcutaneous implantation. This method provides a novel and easy way of fabricating antibiotic loaded polymer scaffolds for varieties of applications.

Effectiveness of Polyglycolic Acid Sheet Covering and Platelet-Rich Plasma after Video-Assisted Thoracic Surgery for Spontaneous Pneumothorax.

Background Video-assisted thoracic surgery (VATS) is widely used for the treatment of spontaneous pneumothorax, and the recurrence rate is high. The goal of the study was to examine the use of polyglycolic acid (PGA) sheets, together with platelet-rich plasma (PRP) from autologous blood for the prevention of postoperative recurrence of spontaneous pneumothorax. Materials and Methods We performed a retrospective study of 65 patients who underwent VATS for spontaneous pneumothorax from March 2008 to November 2011. The patients were divided into groups: without reinforcement (Group A, n = 33) and with reinforcement of the visceral pleura around the staple lines with the PGA sheet and PRP (Group B, n = 32). The postoperative follow-up period was 18 months. Results Chest tubes were used for 3.4 and 3.1 days in Groups A and B, respectively, with no significant difference between the groups. However, the recurrence rate (18.2%; 6 cases) in Group A was significantly higher than that in Group B (p = 0.02). The recurrence rates in patients younger than 25 years in Group A and Group B were 26.1 and 0.0%, respectively (p = 0.03). In Group A, the mean age with recurrence (18.3 years old) was significantly lower than the mean age without recurrence (p = 0.03). Conclusion These results suggest that the use of PGA sheets and PRP might be effective for the prevention of postoperative recurrence of spontaneous pneumothorax.

Toxicity, pharmacokinetics, and in vivo efficacy of biotinylated chitosan surface-modified PLGA nanoparticles for tumor therapy.

Based on our previous work on the PLGA nanoparticles modified with biotinylated chitosan (Bio-CS-PLGA NPs), we further studied the stability, toxicity, pharmacokinetics, and in vivo efficacy. The safety of NPs was studied through single-dose toxicity test in mice, and the result showed that NPs were well tolerated at the dose of 300 mg/kg. Compared with the free EPB group, the NPs group exhibited higher plasma drug concentration, longer half-life time. EPB-loaded NPs significantly inhibited the tumor growth compared to free EPB. All results suggested that Bio-CS-PLGA NPs were stable, safe, and showed a promising potential on targeted drug delivery.

Investigation of DNA damage in cells exposed to poly (lactic-co-glycolic acid) microspheres.

Poly (lactic-co-glycolic acid) (PLGA)-based materials are widely investigated for drug delivery and tissue engineering applications. Despite their popularity the genotoxic potential of PLGA has not been investigated. In this study, the comet assay, a sensitive assay for DNA damage, was used to evaluate potential genotoxicity in model cell types exposed to PLGA microspheres. Human umbilical vein endothelial cells (HUVECs) and mesenchymal stem cells (MSCs) cells were exposed to PLGA microspheres (0.4-6 mg/mL) and DNA damage assessed at 24 h, 4 days, and 7 days. DNA damage was not identified after 24 h. However, after 4 and 7 days of exposure to 2 and 6 mg/mL of PLGA microspheres a significant elevation of DNA damage in both cell types was observed. The PLGA microspheres did not exhibit any cytotoxic effects on the cells under the conditions tested. Our results suggest that PLGA may have a genotoxic effect on cells. A broader investigation of the PLGA genotoxic profile in biological systems is needed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 284-291, 2017.

Foreign-Body Reaction and Osteolysis in Dorsal Lunate Dislocation Repair With Bioabsorbable Suture Anchor.

Background: In recent years the use of biodegradable suture anchors for treating tendon and ligament pathology in hand surgery became popular. These materials are biocompatible, radiolucent, and load sharing, as they incrementally transfer load to surrounding bone during the resorption process. Despite these numerous advantages, polyglycolic (PGA) and poly-L-lactic acid (PLLA) have become a problem because of the potential risk for foreign body reactions. Methods: This article presents a case of an intraosseous foreign body reaction and massive osteolysis of the proximal carpal after dorsal lunate dislocation repair with bioabsorbable suture anchors. Results: Because of the persistent pain and the decreased strength, a proximal row carpectomy was performed 12-months after the initial trauma. Conclusions: Hand surgeons should be aware of the possibility of a late foreign body reaction, that could be especially severe in carpal bones.

Unabsorbed dura patch removed eight years after pituitary surgery.

The Codman ETHISORB Dura Patch is a synthetic, absorbable material whose absorption is complete within approximately 90 days. We report the first case of an unabsorbed Codman Dura patch, in which a patient was presented with nasal obstruction and epistaxis 8 years after pituitary surgery for Cushing's disease.

Respirable controlled release polymeric colloid (RCRPC) of bosentan for the management of pulmonary hypertension: in vitro aerosolization, histological examination and in vivo pulmonary absorption.

Bosentan is an endothelin receptor antagonist (ERA) prescribed for patients with pulmonary arterial hypertension (PAH). The oral delivery of bosentan possesses several drawbacks such as low bioavailability (about 50%), short duration of action, frequent administration, hepatotoxicity and systemic hypotension. The pulmonary administration would circumvent the pre-systemic metabolism thus improving the bioavailability and avoids the systemic adverse effects of oral bosentan. However, the short duration of action and the frequent administration are the major drawbacks of inhalation therapy. Thus, the aim of this work is to explore the potential of respirable controlled release polymeric colloid (RCRPC) for effective, safe and sustained pulmonary delivery of bosentan. Central composite design was adopted to study the influence of formulation and process variables on nanoparticles properties. The particle size, polydispersity index (PDI), entrapment efficiency (EE) and in vitro bosentan released were selected as dependent variables. The optimized RCRPC showed particle size of 420 nm, PDI of 0.39, EE of 60.5% and sustained release pattern where only 31.0% was released after 16 h. The in vitro nebulization of RCRPC indicated that PLGA nanoparticles could be incorporated into respirable nebulized droplets better than drug solution. Pharmacokinetics and histopathological examination were determined after intratracheal administration of the developed RCRPC to male albino rats compared to the oral bosentan suspension. Results revealed the great improvement of bioavailability (12.71 folds) and sustained vasodilation effect on the pulmonary blood vessels (more than 12 h). Bosentan-loaded RCRPC administered via the pulmonary route may therefore constitute an advance in the management of PAH.

In Vivo Assessment of Bone Regeneration in Alginate/Bone ECM Hydrogels with Incorporated Skeletal Stem Cells and Single Growth Factors.

The current study has investigated the use of decellularised, demineralised bone extracellular matrix (ECM) hydrogel constructs for in vivo tissue mineralisation and bone formation. Stro-1-enriched human bone marrow stromal cells were incorporated together with select growth factors including VEGF, TGF-ß3, BMP-2, PTHrP and VitD3, to augment bone formation, and mixed with alginate for structural support. Growth factors were delivered through fast (non-osteogenic factors) and slow (osteogenic factors) release PLGA microparticles. Constructs of 5 mm length were implanted in vivo for 28 days within mice. Dense tissue assessed by micro-CT correlated with histologically assessed mineralised bone formation in all constructs. Exogenous growth factor addition did not enhance bone formation further compared to alginate/bone ECM (ALG/ECM) hydrogels alone. UV irradiation reduced bone formation through degradation of intrinsic growth factors within the bone ECM component and possibly also ECM cross-linking. BMP-2 and VitD3 rescued osteogenic induction. ALG/ECM hydrogels appeared highly osteoinductive and delivery of angiogenic or chondrogenic growth factors led to altered bone formation. All constructs demonstrated extensive host tissue invasion and vascularisation aiding integration and implant longevity. The proposed hydrogel system functioned without the need for growth factor incorporation or an exogenous inducible cell source. Optimal growth factor concentrations and spatiotemporal release profiles require further assessment, as the bone ECM component may suffer batch variability between donor materials. In summary, ALG/ECM hydrogels provide a versatile biomaterial scaffold for utilisation within regenerative medicine which may be tailored, ultimately, to form the tissue of choice through incorporation of select growth factors.

Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

We prepared a bone scaffold material comprising a PLGA/ß-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/ß-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/ß-TCP composite scaffold material (P < 0.05). An in vivo test indicated that the bone scaffold material with core-cladding structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/ß-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

Perianchor Cyst Formation Around Biocomposite Biodegradable Suture Anchors After Rotator Cuff Repair.

BACKGROUND: Biodegradable anchors may lead to perianchor cyst formation or osteolysis. A new generation of anchors containing osteoconductive material was recently presented, but there is currently no solid evidence that this concept decreases cyst formation around anchors. HYPOTHESIS: The null hypothesis was that the prevalence and severity of cyst formation around anchors would be similar for all 3 anchor types. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: To evaluate differences between anchor behaviors postoperatively, this study included 2 groups of patients who underwent rotator cuff repair. In group 1 (n = 38), transosseous-equivalent rotator cuff repair was performed in all patients. At the time of repair, 2 different anchors (anchor A: 23% microstructured ß-tricalcium phosphate plus 77% polylactic acid enantiomers [PLLA]; and anchor B: 30% hydroxyapatite plus 70% PLLA) were used for medial-row repair. Insertion locations (anterior or posterior) were randomly assigned. In group 2 (n = 38), the same procedure was performed; however, 1 of the anchors used in group 1 was changed (anchor A: as above; and anchor C: 30% ß-tricalcium phosphate plus 70% faster absorbing polylactic-co-glycolic acid copolymer [85% PLLA plus 15% polyglycolic acid]). The presence and severity of fluid collection around the anchors was evaluated by magnetic resonance imaging at approximately 1 year after rotator cuff repair (12.7 ± 0.9 months for group 1 and 12.6 ± 1.8 months for group 2). RESULTS: In group 1, a fluid signal was observed in 14 patients (36.8%) for anchor A and in 12 patients (31.6%) for anchor B (P > .05). The severity of perianchor cyst formation was no different for the 2 anchors (respective fluid signal grades [0-4]: 24, 3, 9, 1, and 1 for anchor A; and 26, 4, 7, 1, and 0 for anchor B; P > .05). However, in group 2, cysts were observed in 19 patients (50%) for anchor A and in 3 patients (7.9%) for anchor C (P < .001). For anchor C, only 2 cases of grade 1 and 1 case of grade 2 fluid collection were observed. Intergroup analysis of anchor A revealed no significant differences in the prevalence or severity of perianchor cyst formation (P > .05). Healing failure was observed in 12 patients (31.6%) in group 1 and 10 patients (26.3%) in group 2 (P > .05). CONCLUSION: New-generation biodegradable suture anchors seem to decrease the severity of perianchor cyst formation. Future research is required to optimize the compositions and proportions of osteoconductive materials and polymers to improve adverse reactions. Nevertheless, controlling the properties of polymers and adding osteoconductive material both appear to enhance biocompatibility.

PLGA nanoparticle formulation of RK-33: an RNA helicase inhibitor against DDX3.

BACKGROUND: The DDX3 helicase inhibitor RK-33 is a newly developed anticancer agent that showed promising results in preclinical research (Bol et al. EMBO Mol Med, 7(5):648-649, 2015). However, due to the physicochemical and pharmacological characteristics of RK-33, we initiated development of alternative formulations of RK-33 by preparing sustained release nanoparticles that can be administered intravenously. METHODS: In this study, RK-33 was encapsulated in poly(lactic-co-glycolic acid) (PLGA), one of the most well-developed biodegradable polymers, using the emulsion solvent evaporation method. RESULTS: Hydrodynamic diameter of RK-33-PLGA nanoparticles was about 245 nm with a negative charge, and RK-33-PLGA nanoparticles had a payload of 1.4 % RK-33. RK-33 was released from the PLGA nanoparticles over 7 days (90 ± 5.7 % released by day 7) and exhibited cytotoxicity to human breast carcinoma MCF-7 cells in a time-dependent manner. Moreover, RK-33-PLGA nanoparticles were well tolerated, and systemic retention of RK-33 was markedly improved in normal mice. CONCLUSIONS: PLGA nanoparticles have a potential as a parenteral formulation of RK-33.

PLGA-Based Nanoparticles: a Safe and Suitable Delivery Platform for Osteoarticular Pathologies.

PURPOSE: Despite the promising applications of PLGA based particles, studies examining the fate and consequences of these particles after intra-articular administration in the joint are scanty. This study was carried out to evaluate the neutrality of the unloaded delivery system on different articular cell types. To facilitate tracking, we have thus developed a fluorescent core of particles, combined to a hyaluronate shell for cell recognition. METHODS: Fluorescence pictures were taken at time intervals to assess the internalization and the corresponding inflammatory response was monitored by RT-qPCR and biochemical measurements. After NPs pre-treatment, mesenchymal stem cells (MSCs) were cultured into chondrogenic, adipogenic or osteogenic differentiation media, to investigate if NPs exposure interferes with differentiation ability. Finally, intra-articular injections were performed in healthy rat knees and joint's structure analysed by histological studies. RESULTS: Particles were detected in cytoplasm 8 h after exposure. Internalization led to a slight and reversible increase of inflammatory markers, but lower than in inflammatory conditions. We have confirmed particles exposure minimal neutrality on MSCs pluripotency. Histological exams of joint after intra-articular injections do not demonstrate any side effects of NPs. CONCLUSIONS: Our findings suggest that such a delivery platform is well tolerated locally and could be used to deliver active molecules to the joint.

Development of surface modified biodegradable polymeric nanoparticles to deliver GSE24.2 peptide to cells: a promising approach for the treatment of defective telomerase disorders.

The aim of the present study was to develop a novel strategy to deliver intracellularly the peptide GSE24.2 for the treatment of Dyskeratosis congenita (DC) and other defective telomerase disorders. For this purpose, biodegradable polymeric nanoparticles using poly(lactic-co-glycolic acid) (PLGA NPs) or poly(lactic-co-glycolic acid)-poly ethylene glycol (PLGA-PEG NPs) attached to either polycations or cell-penetrating peptides (CPPs) were prepared in order to increase their cellular uptake. The particles exhibited an adequate size and zeta potential, with good peptide loading and a biphasic pattern obtained in the in vitro release assay, showing an initial burst release and a later sustained release. GSE24.2 structural integrity after encapsulation was assessed using SDS-PAGE, revealing an unaltered peptide after the NPs elaboration. According to the cytotoxicity results, cell viability was not affected by uncoated polymeric NPs, but the incorporation of surface modifiers slightly decreased the viability of cells. The intracellular uptake exhibited a remarkable improvement of the internalization, when the NPs were conjugated to the CPPs. Finally, the bioactivity, addressed by measuring DNA damage rescue and telomerase reactivation, showed that some formulations had the lowest cytotoxicity and highest biological activity. These results proved that GSE24.2-loaded NPs could be delivered to cells, and therefore, become an effective approach for the treatment of DC and other defective telomerase syndromes.