by Keyword: Therapy
Maier, Martina, Rubio Ballester, Belén, Duff, Armin, Duarte Oller, Esther, Verschure, P., (2019). Effect of specific over nonspecific VR-based rehabilitation on poststroke motor recovery: A systematic meta-analysis Neurorehabilitation and Neural Repair On-line,
Background. Despite the rise of virtual reality (VR)-based interventions in stroke rehabilitation over the past decade, no consensus has been reached on its efficacy. This ostensibly puzzling outcome might not be that surprising given that VR is intrinsically neutral to its use—that is, an intervention is effective because of its ability to mobilize recovery mechanisms, not its technology. As VR systems specifically built for rehabilitation might capitalize better on the advantages of technology to implement neuroscientifically grounded protocols, they might be more effective than those designed for recreational gaming. Objective. We evaluate the efficacy of specific VR (SVR) and nonspecific VR (NSVR) systems for rehabilitating upper-limb function and activity after stroke. Methods. We conducted a systematic search for randomized controlled trials with adult stroke patients to analyze the effect of SVR or NSVR systems versus conventional therapy (CT). Results. We identified 30 studies including 1473 patients. SVR showed a significant impact on body function (standardized mean difference [SMD] = 0.23; 95% CI = 0.10 to 0.36; P = .0007) versus CT, whereas NSVR did not (SMD = 0.16; 95% CI = −0.14 to 0.47; P = .30). This result was replicated in activity measures. Conclusions. Our results suggest that SVR systems are more beneficial than CT for upper-limb recovery, whereas NSVR systems are not. Additionally, we identified 6 principles of neurorehabilitation that are shared across SVR systems and are possibly responsible for their positive effect. These findings may disambiguate the contradictory results found in the current literature.
Keywords: Stroke, Paresis, Virtual reality, Rehabilitation, Occupational therapy, Review
Matera, Carlo, Gomila-Juaneda, Alexandre, Camarero, Núria, Libergoli, Michela, Soler, Concepció, Gorostiza, Pau, (2018). A photoswitchable antimetabolite for targeted photoactivated chemotherapy Journal of the American Chemical Society 140, (46), 15764-15773
The efficacy and tolerability of systemically administered anticancer agents are limited by their off-target effects. Precise spatiotemporal control over their cytotoxic activity would allow improving chemotherapy treatments, and light-regulated drugs are well suited to this purpose. We have developed phototrexate, the first photoswitchable inhibitor of the human dihydrofolate reductase (DHFR), as a photochromic analog of methotrexate, a widely prescribed chemotherapeutic drug to treat cancer and psoriasis. Quantification of the light-regulated DHFR enzymatic activity, cell proliferation, and in vivo effects in zebrafish show that phototrexate behaves as a potent antifolate in its photoactivated cis configuration, and that it is nearly inactive in its dark-relaxed trans form. Thus, phototrexate constitutes a proof-of-concept to design light-regulated cytotoxic small molecules, and a step forward to develop targeted anticancer photochemotherapies with localized efficacy and reduced adverse effects.
Keywords: Photopharmacology, Photodynamic therapy, Antiproliferative, Arthritis, Psoriasis, Nanomedicine
Ballester, Rubio Belén, Nirme, Jens, Camacho, Irene, Duarte, Esther, Rodríguez, Susana, Cuxart, Ampar, Duff, Armin, Verschure, F. M. J. Paul, (2017). Domiciliary VR-based therapy for functional recovery and cortical reorganization: Randomized controlled trial in participants at the chronic stage post stroke JMIR Serious Games , 5, (3), e15
Background: Most stroke survivors continue to experience motor impairments even after hospital discharge. Virtual reality-based techniques have shown potential for rehabilitative training of these motor impairments. Here we assess the impact of at-home VR-based motor training on functional motor recovery, corticospinal excitability and cortical reorganization. Objective: The aim of this study was to identify the effects of home-based VR-based motor rehabilitation on (1) cortical reorganization, (2) corticospinal tract, and (3) functional recovery after stroke in comparison to home-based occupational therapy. Methods: We conducted a parallel-group, controlled trial to compare the effectiveness of domiciliary VR-based therapy with occupational therapy in inducing motor recovery of the upper extremities. A total of 35 participants with chronic stroke underwent 3 weeks of home-based treatment. A group of subjects was trained using a VR-based system for motor rehabilitation, while the control group followed a conventional therapy. Motor function was evaluated at baseline, after the intervention, and at 12-weeks follow-up. In a subgroup of subjects, we used Navigated Brain Stimulation (NBS) procedures to measure the effect of the interventions on corticospinal excitability and cortical reorganization. Results: Results from the system?s recordings and clinical evaluation showed significantly greater functional recovery for the experimental group when compared with the control group (1.53, SD 2.4 in Chedoke Arm and Hand Activity Inventory). However, functional improvements did not reach clinical significance. After the therapy, physiological measures obtained from a subgroup of subjects revealed an increased corticospinal excitability for distal muscles driven by the pathological hemisphere, that is, abductor pollicis brevis. We also observed a displacement of the centroid of the cortical map for each tested muscle in the damaged hemisphere, which strongly correlated with improvements in clinical scales. Conclusions: These findings suggest that, in chronic stages, remote delivery of customized VR-based motor training promotes functional gains that are accompanied by neuroplastic changes. Trial Registration: International Standard Randomized Controlled Trial Number NCT02699398 (Archived by ClinicalTrials.gov at https://clinicaltrials.gov/ct2/show/NCT02699398?term=NCT02699398&rank=1)
Keywords: Stroke, Movement disorder, Recovery of function, neuroplasticity, Transcranial magnetic stimulation, Physical therapy, Hemiparesis, Computer applications software
Noguera-Ortega, Estela, Secanella-Fandos, Silvia, Eraña, Hasier, Gasión, Jofre, Rabanal, Rosa M., Luquin, Marina, Torrents, Eduard, Julián, Esther, (2016). Nonpathogenic Mycobacterium brumae inhibits bladder cancer growth in vitro, ex vivo, and in vivo European Urology Focus , 2, (1), 67-76
Bacillus Calmette-Guérin (BCG) prevents tumour recurrence and progression in non–muscle-invasive bladder cancer (BC). However, common adverse events occur, including BCG infections.
To find a mycobacterium with similar or superior antitumour activity to BCG but with greater safety.
In vitro, ex vivo, and in vivo comparisons of the antitumour efficacy of nonpathogenic mycobacteria and BCG.
The in vitro antitumour activity of a broad set of mycobacteria was studied in seven different BC cell lines. The most efficacious was selected and its ex vivo capacity to activate immune cells and its in vivo antitumour activity in an orthotopic murine model of BC were investigated.
Outcome measurements and statistical analysis
Growth inhibition of BC cells was the primary outcome measurement. Parametric and nonparametric tests were use to analyse the in vitro results, and a Kaplan-Meier test was applied to measure survival in mycobacteria-treated tumour-bearing mice.
Results and limitations
Mycobacterium brumae is superior to BCG in inhibiting low-grade BC cell growth, and has similar effects to BCG against high-grade cells. M. brumae triggers an indirect antitumour response by activating macrophages and the cytotoxic activity of peripheral blood cells against BC cells. Although no significant differences were observed between BCG and M. brumae treatments in mice, M. brumae treatment prolonged survival in comparison to BCG treatment in tumour-bearing mice. In contrast to BCG, M. brumae does not persist intracellularly or in tumour-bearing mice, so the risk of infection is lower.
Our preclinical data suggest that M. brumae represents a safe and efficacious candidate as a therapeutic agent for non–muscle-invasive BC.
We investigated the antitumour activity of nonpathogenic mycobacteria in in vitro and in vivo models of non–muscle-invasive bladder cancer. We found that Mycobacterium brumae effectively inhibits bladder cancer growth and helps the host immune system to eradicate cancer cells, and is a promising agent for antitumour immunotherapy.
Keywords: Animal models, Bacillus Calmette-Guérin, Cytokines, Immunomodulation, Immunotherapy, Mycobacteria, Urothelial cell line
Moles, E., Moll, K., Ch'ng, J. H., Parini, P., Wahlgren, M., Fernàndez-Busquets, X., (2016). Development of drug-loaded immunoliposomes for the selective targeting and elimination of rosetting Plasmodium falciparum-infected red blood cells Journal of Controlled Release , 241, 57-67
Parasite proteins exported to the surface of Plasmodium falciparum-parasitized red blood cells (pRBCs) have a major role in severe malaria clinical manifestation, where pRBC cytoadhesion and rosetting processes have been strongly linked with microvascular sequestration while avoiding both spleen filtration and immune surveillance. The parasite-derived and pRBC surface-exposed PfEMP1 protein has been identified as one of the responsible elements for rosetting and, therefore, considered as a promising vaccine candidate for the generation of rosette-disrupting antibodies against severe malaria. However, the potential role of anti-rosetting antibodies as targeting molecules for the functionalization of antimalarial drug-loaded nanovectors has never been studied. Our manuscript presents a proof-of-concept study where the activity of an immunoliposomal vehicle with a dual performance capable of specifically recognizing and disrupting rosettes while simultaneously eliminating those pRBCs forming them has been assayed in vitro. A polyclonal antibody against the NTS-DBL1α N-terminal domain of a rosetting PfEMP1 variant has been selected as targeting molecule and lumefantrine as the antimalarial payload. After 30 min incubation with 2 μM encapsulated drug, a 70% growth inhibition for all parasitic forms in culture (IC50: 414 nM) and a reduction in ca. 60% of those pRBCs with a rosetting phenotype (IC50: 747 nM) were achieved. This immunoliposomal approach represents an innovative combination therapy for the improvement of severe malaria therapeutics having a broader spectrum of activity than either anti-rosetting antibodies or free drugs on their own.
Keywords: Combination therapy, Immunoliposomes, Malaria, Nanomedicine, Rosetting, Targeted drug delivery
Giannotti, M. I., Abasolo, Ibane, Oliva, Mireia, Andrade, Fernanda, García-Aranda, Natalia, Melgarejo, Marta, Pulido, Daniel, Corchero, José Luis, Fernández, Yolanda, Villaverde, Antonio, Royo, Miriam, Garcia-Parajo, Maria F., Sanz, Fausto, Schwartz Jr, Simó, (2016). Highly versatile polyelectrolyte complexes for improving the enzyme replacement therapy of lysosomal storage disorders ACS Applied Materials & Interfaces , 8, (39), 25741–25752
Lysosomal storage disorders are currently treated by enzyme replacement therapy (ERT) through the direct administration of the unprotected recombinant protein to the patients. Herein we present an ionically cross-linked polyelectrolyte complex (PEC) composed of trimethyl chitosan (TMC) and α-galactosidase A (GLA), the defective enzyme in Fabry disease, with the capability of directly targeting endothelial cells by incorporating peptide ligands containing the RGD sequence. We assessed the physicochemical properties, cytotoxicity, and hemocompatibility of RGD-targeted and untargeted PECs, the uptake by endothelial cells and the intracellular activity of PECs in cell culture models of Fabry disease. Moreover, we also explored the effect of different freeze-drying procedures in the overall activity of the PECs. Our results indicate that the use of integrin-binding RGD moiety within the PEC increases their uptake and the efficacy of the GLA enzyme, while the freeze-drying allows the activity of the therapeutic protein to remain intact. Overall, these results highlight the potential of TMC-based PECs as a highly versatile and feasible drug delivery system for improving the ERT of lysosomal storage disorders.
Keywords: Enzyme replacement therapy, Fabry disease, Lysosomal delivery, Nanomedicine, Polyelectrolyte complexes, Trimethyl chitosan, α-galactosidase A
Noguera-Ortega, E., Rabanal, R. M., Secanella-Fandos, S., Torrents, E., Luquin, M., Julián, E., (2016). Gamma-irradiated mycobacteria enhance survival in bladder tumor bearing mice although less efficaciously than live mycobacteria Journal of Urology , 195, (1), 198-205
γ Irradiated Mycobacterium bovis bacillus Calmette-Guérin has shown in vitro and ex vivo antitumor activity. However, to our knowledge the potential antitumor capacity has not been demonstrated in vivo. We studied the in vivo potential of γ irradiated bacillus Calmette-Guérin and γ irradiated M. brumae, a saprophytic mycobacterium that was recently described as an immunotherapeutic agent.
Materials and Methods
The antitumor capacity of γ irradiated M. brumae was first investigated by analyzing the in vitro inhibition of bladder tumor cell proliferation and the ex vivo cytotoxic effect of M. brumae activated peripheral blood cells. The effect of γ irradiated M. brumae or bacillus Calmette-Guérin intravesical treatment was then compared to treatment with live mycobacteria in the orthotopic murine model of bladder cancer.
Nonviable M. brumae showed a capacity to inhibit in vitro bladder cancer cell lines similar to that of live mycobacteria. However, its capacity to induce cytokine production was decreased compared to that of live M. brumae. γ Irradiated M. brumae could activate immune cells to inhibit tumor cell growth, although to a lesser extent than live mycobacteria. Finally, intravesical treatment with γ irradiated M. brumae or bacillus Calmette-Guérin significantly increased survival with respect to that of nontreated tumor bearing mice. Both γ irradiated mycobacteria showed lower survival rates than those of live mycobacteria but the minor efficacy of γ irradiated vs live mycobacteria was only significant for bacillus Calmette-Guérin.
Our results show that although γ irradiated mycobacteria is less efficacious than live mycobacteria, it induces an antitumor effect in vivo, avoiding the possibility of further mycobacterial infections.
Keywords: BCG vaccine, Gamma rays, Immunotherapy, Mycobacterium, Urinary bladder neoplasms
Levato, R., Planell, J. A., Mateos-Timoneda, M. A., Engel, E., (2015). Role of ECM/peptide coatings on SDF-1α triggered mesenchymal stromal cell migration from microcarriers for cell therapy Acta Biomaterialia 18, 59-67
Many cell therapies rely on the ability of mesenchymal stromal cells (MSCs) to diffuse and localize throughout the target tissue-such as tumoral and ischemic tissues-, in response to specific cytokine signals, rather than being concentrated at the site of implantation. Therefore, it is fundamental to engineer biomaterial carriers as reservoirs, from which cells can migrate, possibly in a controlled manner. In this work, microcarriers (Î¼Cs) made of polylactic acid are characterized as MSC delivery vehicles capable of modulating key chemotactic pathways. The effect of different functionalization strategies on MSC migratory behavior from the Î¼Cs is studied in vitro in relation to SDF-1Î±/CXCR4 axis,-a major actor in MSC recruitment, chemotaxis and homing. Collagen and arginine-glycine-aspartic acid (RGD) peptides were either covalently grafted or physisorbed on Î¼C surface. While stable covalent modifications promoted better cell adhesion and higher proliferation compared to physisorption, the functionalization method of the Î¼Cs also affected the cells migratory behavior in response to SDF-1Î± (CXCL12) stimulation. Less stable coatings (physisorbed) showed sensibly higher number of migrating cells than covalent collagen/RGD coatings. The combination of physic-chemical cues provided by protein/peptide functionalization and stimuli induced by 3D culture on Î¼Cs improved MSC expression of CXCR4, and exerted a control over cell migration, a condition suitable to promote cell homing after transplantation in vivo. These are key findings to highlight the impact of surface modification approaches on chemokine-triggered cell release, and allow designing biomaterials for efficient and controlled cell delivery to damaged tissues.
Keywords: Cell therapy, Chemotaxis, ECM (extracellular matrix), Mesenchymal stromal cells, Surface modification
Isetta, V., León, C., Torres, M., Embid, C., Roca, J., Navajas, D., Farré, R., Montserrat, J. M., (2014). Telemedicine-based approach for obstructive sleep apnea management: Building evidence Interactive Journal of Medical Research , 3, (1), e6
Background: Telemedicine seems to offer reliable solutions to health care challenges, but significant contradictory results were recently found. Therefore, it is crucial to carefully select outcomes and target patients who may take advantage of this technology. Continuous positive airway pressure (CPAP) therapy compliance is essential to treat patients with obstructive sleep apnea (OSA). We believe that OSA patients could benefit greatly from a telemedicine approach for CPAP therapy management. Objective: The objective of our study was to evaluate the application of a telemedicine-based approach in the CPAP therapy management, focusing on patients' CPAP follow-up and training. Methods: We performed two studies. First, (study 1) we enrolled 50 consecutive OSA patients who came to our sleep center for the CPAP follow-up visit. Patients performed a teleconsultation with a physician, and once finalized, they were asked to answer anonymously to a questionnaire regarding their opinion about the teleconsultation. In a second randomized controlled trial (RCT) (study 2). we included 40 OSA patients scheduled for CPAP training. There were 20 that received the usual face-to-face training and 20 that received the training via videoconference. After the session, they were blindly evaluated on what they learned about OSA and mask placement. Results: More than 95% (49/50) of the interviewed patients were satisfied with the teleconsultation, and 66% (33/50) of them answered that the teleconsultation could replace 50%-100% of their CPAP follow-up visits. Regarding the RCT patients who received the CPAP training via videoconference demonstrated the same knowledge about OSA and CPAP therapy as the face-to-face group (mean 93.6% of correct answers vs mean 92.1%; P=.935). Performance on practical skills (mask and headgear placement, leaks avoidance) was also similar between the two groups. Conclusions: OSA patients gave a positive feedback about the use of teleconsultation for CPAP follow-up, and the CPAP training based on a telemedicine approach proved to be as effective as face-to-face training. These results support the use of this telemedicine-based approach as a valuable strategy for patients' CPAP training and clinical follow-up.
Keywords: CPAP therapy, Sleep apnea, Teleconsultation, Telemedicine
Navarro, S., Moleiro, V., Molina-Estevez, F. J., Lozano, M. L., Chinchon, R., Almarza, E., Quintana-Bustamante, O., Mostoslavsky, G., Maetzig, T., Galla, M., Heinz, N., Schiedlmeier, B., Torres, Y., Modlich, U., Samper, E., Río, P., Segovia, J. C., Raya, A., Güenechea, G., Izpisua-Belmonte, J. C., Bueren, J. A., (2014). Generation of iPSCs from genetically corrected Brca2 hypomorphic cells: Implications in cell reprogramming and stem cell therapy Stem Cells , 32, (2), 436-446
Fanconi anemia (FA) is a complex genetic disease associated with a defective DNA repair pathway known as the FA pathway. In contrast to many other FA proteins, BRCA2 participates downstream in this pathway and has a critical role in homology-directed recombination (HDR). In our current studies, we have observed an extremely low reprogramming efficiency in cells with a hypomorphic mutation in Brca2 (Brca2Î”27/Î”27), that was associated with increased apoptosis and defective generation of nuclear RAD51 foci during the reprogramming process. Gene complementation facilitated the generation of Brca2Î”27/Î”27 induced pluripotent stem cells (iPSCs) with a disease-free FA phenotype. Karyotype analyses and comparative genome hybridization arrays of complemented Brca2Î”27/Î”27 iPSCs showed, however, the presence of different genetic alterations in these cells, most of which were not evident in their parental Brca2 Î”27/Î”27 mouse embryonic fibroblasts. Gene-corrected Brca2Î”27/Î”27 iPSCs could be differentiated in vitro toward the hematopoietic lineage, although with a more limited efficacy than WT iPSCs or mouse embryonic stem cells, and did not engraft in irradiated Brca2Î”27/Î”27 recipients. Our results are consistent with previous studies proposing that HDR is critical for cell reprogramming and demonstrate that reprogramming defects characteristic of Brca2 mutant cells can be efficiently overcome by gene complementation. Finally, based on analysis of the phenotype, genetic stability, and hematopoietic differentiation potential of gene-corrected Brca2Î”27/Î”27 iPSCs, achievements and limitations in the application of current reprogramming approaches in hematopoietic stem cell therapy are also discussed.
Keywords: Bone marrow aplasia, Cellular therapy, Fanconi anemia, Gene therapy, Hematopoietic stem cells, Induced pluripotent stem cells
Bueno, M., Paganetti, H., Duch, M. A., Schuemann, J., (2013). An algorithm to assess the need for clinical Monte Carlo dose calculation for small proton therapy fields based on quantification of tissue heterogeneity Medical Physics , 40, (8), 081704
Purpose: In proton therapy, complex density heterogeneities within the beam path constitute a challenge to dose calculation algorithms. This might question the reliability of dose distributions predicted by treatment planning systems based on analytical dose calculation. For cases in which substantial dose errors are expected, resorting to Monte Carlo dose calculations might be essential to ensure a successful treatment outcome and therefore the benefit is worth a presumably long computation time. The aim of this study was to define an indicator for the accuracy of dose delivery based on analytical dose calculations in treatment planning systems for small proton therapy fields to identify those patients for which Monte Carlo dose calculation is warranted. Methods: Fourteen patients treated at our facility with small passively scattered proton beams (apertures diameters below 7 cm) were selected. Plans were generated in the XiO treatment planning system in combination with a pencil beam algorithm developed at the Massachusetts General Hospital and compared to Monte Carlo dose calculations. Differences in the dose to the 50% of the gross tumor volume (D50, GTV) were assessed in a field-by-field basis. A simple and fast methodology was developed to quantify the inhomogeneity of the tissue traversed by a single small proton beam using a heterogeneity index (HI) - a concept presented by Plugfelder [Med. Phys. 34, 1506-1513 (2007)10.1118/1. 2710329] for scanned proton beams. Finally, the potential correlation between the error made by the pencil beam based treatment planning algorithm for each field and the level of tissue heterogeneity traversed by the proton beam given by the HI was evaluated. Results: Discrepancies up to 5.4% were found in D50 for single fields, although dose differences were within clinical tolerance levels (<3%) when combining all of the fields involved in the treatment. The discrepancies found for each field exhibited a strong correlation to their associated HI-values (Spearman's Ï = 0.8, p < 0.0001); the higher the level of tissue inhomogeneities for a particular field, the larger the error by the analytical algorithm. With the established correlation a threshold for HI can be set by choosing a tolerance level of 2-3% - commonly accepted in radiotherapy. Conclusions: The HI is a good indicator for the accuracy of proton field delivery in terms of GTV prescription dose coverage when small fields are delivered. Each HI-value was obtained from the CT image in less than 3 min on a computer with 2 GHz CPU allowing implementation of this methodology in clinical routine. For HI-values exceeding the threshold, either a change in beam direction (if feasible) or a recalculation of the dose with Monte Carlo would be highly recommended.
Keywords: Heterogeneities, Heterogeneity index, Monte Carlo, Proton therapy, Small fields
Chimenti, L., Luque, T., Bonsignore, M. R., Ramirez, J., Navajas, D., Farre, R., (2012). Pre-treatment with mesenchymal stem cells reduces ventilator-induced lung injury European Respiratory Journal , 40, (4), 939-948
Bone marrow-derived mesenchymal stem cells (MSCs) reduce acute lung injury in animals challenged by bleomycin or bacterial lipopolysaccaride. It is not known, however, whether MSCs protect from ventilator-induced lung injury (VILI). This study investigated whether MSCs have a potential role in preventing or modulating VILI in healthy rats subjected to high-volume ventilation. 24 Sprague-Dawley rats (250-300 g) were subjected to high-volume mechanical ventilation (25 mL.kg(-1)). MSCs (5 x 10(6)) were intravenously or intratracheally administered (n=8 each) 30 min before starting over-ventilation and eight rats were MSC-untreated. Spontaneously breathing anesthetised rats (n=8) served as controls. After 3 h of over-ventilation or control the animals were sacrificed and lung tissue and bronchoalveolar lavage fluid (BALF) were sampled for further analysis. When compared with controls, MSC-untreated over-ventilated rats exhibited typical VILI features. Lung oedema, histological lung injury index, concentrations of total protein, interleukin-1 beta, macrophage inflammatory protein-2 and number of neutrophils in BALF and vascular cell adhesion protein-1 in lung tissue significantly increased in over-ventilated rats. All these indices of VILI moved significantly towards normalisation in the rats treated with MSCs, whether intravenously or intratracheally. Both local and systemic pre-treatment with MSCs reduced VILI in a rat model.
Keywords: Acute lung injury, Cell therapy, Injurious ventilation, Lung inflammation, Lung oedema, Mechanical ventilation
Urban, Patricia, Estelrich, Joan, Cortés, Alfred, Fernàndez-Busquets, X., (2011). A nanovector with complete discrimination for targeted delivery to Plasmodium falciparum-infected versus non-infected red blood cells in vitro Journal of Controlled Release , 151, (2), 202-211
Current administration methods of antimalarial drugs deliver the free compound in the blood stream, where it can be unspecifically taken up by all cells, and not only by Plasmodium-infected red blood cells (pRBCs). Nanosized carriers have been receiving special attention with the aim of minimizing the side effects of malaria therapy by increasing drug bioavailability and selectivity. Liposome encapsulation has been assayed for the delivery of compounds against murine malaria, but there is a lack of cellular studies on the performance of targeted liposomes in specific cell recognition and on the efficacy of cargo delivery, and very little data on liposome-driven antimalarial drug targeting to human-infecting parasites. We have used fluorescence microscopy to assess in vitro the efficiency of liposomal nanocarriers for the targeted delivery of their contents to pRBCs. 200-nm liposomes loaded with quantum dots were covalently functionalized with oriented, specific half-antibodies against P. falciparum late form-infected pRBCs. In less than 90 min, liposomes dock to pRBC plasma membranes and release their cargo to the cell. 100.0% of late form-containing pRBCs and 0.0% of non-infected RBCs in P. falciparum cultures are recognized and permeated by the content of targeted immunoliposomes. Liposomes not functionalized with antibodies are also specifically directed to pRBCs, although with less affinity than immunoliposomes. In preliminary assays, the antimalarial drug chloroquine at a concentration of 2 nM, >= 10 times below its IC50 in solution, cleared 26.7 ± 1.8% of pRBCs when delivered inside targeted immunoliposomes.
Keywords: Antimalarial chemotherapy, Chloroquine, Half-antibodies, Immunoliposomes, Malaria, Nanomedicine
Hosta, L., Pla, M., Arbiol, J., Lopez-Iglesias, C., Samitier, J., Cruz, L. J., Kogan, M. J., Albericio, F., (2009). Conjugation of Kahalalide F with gold nanoparticles to enhance in vitro antitumoral activity Bioconjugate Chemistry , 20, (1), 138-146
Two Cys-containing analogues of the anticancer drug Kahalalide F are synthesized and conjugated to 20 and 40 nm gold nanoparticles (GNPs). The resulting complexes are characterized by different analytical techniques to confirm the attachment of peptide to the GNPs. The self-assembly capacity of a peptide dramatically influences the final ratio number of molecules per nanoparticle, saturating the nanoparticle surface and prompting multilayered capping on the surface. In such way, the nanoparticle could act as a concentrator for the delivery of drugs, thereby increasing bioactivity. The GNP sizes and the conjugation have influence on the biological activities. Kahalalide F analogues conjugated with GNPs are located subcellularly at lysosome-like bodies, which may be related to the action mechanism of Kahalalide F. The results suggest that the selective delivery and activity of Kahalalide F analogues can be improved by conjugating the peptides to GNPs.
Keywords: Electrical detection, Cellular uptake, Drug-delivery, Cancer-cells, Peptide, Size, Surface, Absorption, Scattering, Therapy