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1.
PLoS Pathog ; 19(4): e1011286, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37075076

RESUMO

Flaviviruses continue to emerge as global health threats. There are currently no Food and Drug Administration (FDA) approved antiviral treatments for flaviviral infections. Therefore, there is a pressing need to identify host and viral factors that can be targeted for effective therapeutic intervention. Type I interferon (IFN-I) production in response to microbial products is one of the host's first line of defense against invading pathogens. Cytidine/uridine monophosphate kinase 2 (CMPK2) is a type I interferon-stimulated gene (ISG) that exerts antiviral effects. However, the molecular mechanism by which CMPK2 inhibits viral replication is unclear. Here, we report that CMPK2 expression restricts Zika virus (ZIKV) replication by specifically inhibiting viral translation and that IFN-I- induced CMPK2 contributes significantly to the overall antiviral response against ZIKV. We demonstrate that expression of CMPK2 results in a significant decrease in the replication of other pathogenic flaviviruses including dengue virus (DENV-2), Kunjin virus (KUNV) and yellow fever virus (YFV). Importantly, we determine that the N-terminal domain (NTD) of CMPK2, which lacks kinase activity, is sufficient to restrict viral translation. Thus, its kinase function is not required for CMPK2's antiviral activity. Furthermore, we identify seven conserved cysteine residues within the NTD as critical for CMPK2 antiviral activity. Thus, these residues may form an unknown functional site in the NTD of CMPK2 contributing to its antiviral function. Finally, we show that mitochondrial localization of CMPK2 is required for its antiviral effects. Given its broad antiviral activity against flaviviruses, CMPK2 is a promising potential pan-flavivirus inhibitor.


Assuntos
Núcleosídeo-Fosfato Quinase , Replicação Viral , Zika virus , Zika virus/fisiologia , Células Vero , Chlorocebus aethiops , Animais , Humanos , Núcleosídeo-Fosfato Quinase/metabolismo , Interferon Tipo I/metabolismo , Flavivirus/fisiologia , Mitocôndrias , Biossíntese de Proteínas
2.
J Drugs Dermatol ; 23(9): 68821s3-68821s14, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39231086

RESUMO

Lipids play an essential role in skin barrier health. With age, there is a natural reduction of physiological lipids such as fatty acids, ceramides, and cholesterol. The triple lipid restore cream is a moisturizer that contains an optimized lipid ratio for aging skin. The cream contains a 2:4:2 ratio of ceramides, cholesterol, and fatty acids that have been shown to best support aging skin. The triple lipid restore cream has been used in combination with energy-based procedures, to provide patients with comprehensive integrated skincare regimens. With limited clinical data and guidelines available in regenerative medicine, real-world cases serve as an invaluable guide for patients and dermatologists in navigating rejuvenation treatment plans. J Drugs Dermatol. 2024;23:9(Suppl 1):s3-14.


Assuntos
Rejuvenescimento , Envelhecimento da Pele , Creme para a Pele , Humanos , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos da radiação , Creme para a Pele/administração & dosagem , Creme para a Pele/química , Feminino , Pessoa de Meia-Idade , Ceramidas/administração & dosagem , Colesterol/administração & dosagem , Resultado do Tratamento , Técnicas Cosméticas , Terapia por Radiofrequência/métodos , Ácidos Graxos/administração & dosagem , Ácidos Graxos/química , Administração Cutânea , Terapia a Laser/métodos , Cicatrização/efeitos dos fármacos , Idoso , Masculino , Agulhas , Indução Percutânea de Colágeno
3.
Proc Natl Acad Sci U S A ; 118(7)2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33526595

RESUMO

Keratinocyte-derived carcinomas, including squamous cell carcinoma (SCC), comprise the most common malignancies. Surgical excision is the therapeutic standard but is not always clinically feasible, and currently available alternatives are limited to superficial tumors. To address the need for a nonsurgical treatment for nodular skin cancers like SCC, we developed a bioadhesive nanoparticle (BNP) drug delivery system composed of biodegradable polymer, poly(lactic acid)-hyperbranched polyglycerol (PLA-HPG), encapsulating camptothecin (CPT). Nanoparticles (NPs) of PLA-HPG are nonadhesive NPs (NNPs), which are stealthy in their native state, but we have previously shown that conversion of the vicinal diols of HPG to aldehydes conferred NPs the ability to form strong covalent bonds with amine-rich surfaces. Herein, we show that these BNPs have significantly enhanced binding to SCC tumor cell surfaces and matrix proteins, thereby significantly enhancing the therapeutic efficacy of intratumoral drug delivery. Tumor injection of BNP-CPT resulted in tumor retention of CPT at ∼50% at 10 d postinjection, while CPT was undetectable in NNP-CPT or free (intralipid) CPT-injected tumors at that time. BNP-CPT also significantly reduced tumor burden, with a portion (∼20%) of BNP-CPT-treated established tumors showing histologic cure. Larger, more fully established PDV SCC tumors treated with a combination of BNP-CPT and immunostimulating CpG oligodeoxynucleotides exhibited enhanced survival relative to controls, revealing the potential for BNP delivery to be used along with local tumor immunotherapy. Taken together, these results indicate that percutaneous delivery of a chemotherapeutic agent via BNPs, with or without adjuvant immunostimulation, represents a viable, nonsurgical alternative for treating cutaneous malignancy.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Nanopartículas/química , Neoplasias Cutâneas/tratamento farmacológico , Adesivos/química , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/administração & dosagem , Camptotecina/uso terapêutico , Linhagem Celular Tumoral , Glicerol/química , Camundongos , Camundongos Endogâmicos C57BL , Poliésteres/química , Polímeros/química
4.
Inorg Chem ; 54(23): 11411-22, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26582548

RESUMO

The PSiP pincer-supported complex ((Cy)PSiP)PdH [(Cy)PSiP = Si(Me)(2-PCy2-C6H4)2] has been implicated as a crucial intermediate in carboxylation of both allenes and boranes. At this stage, however, there is uncertainty regarding the exact structure of ((Cy)PSiP)PdH, especially in solution. Previously, both a Pd(II) structure with a terminal Pd hydride and a Pd(0) structure featuring an η(2)-silane have been proposed. In this contribution, a range of techniques were used to establish that ((Cy)PSiP)PdH and the related Pt species, ((Cy)PSiP)PtH, are true M(II) hydrides in both the solid state and solution. The single-crystal X-ray structures of ((Cy)PSiP)MH (M = Pd and Pt) and the related species ((iPr)PSiP)PdH [(iPr)PSiP = Si(Me)(2-P(i)Pr2-C6H4)2] are in agreement with the presence of a terminal metal hydride, and the exact geometry of ((Cy)PSiP)PtH was confirmed using neutron diffraction. The (1)H and (29)Si{(1)H}NMR chemical shifts of ((Cy)PSiP)MH (M = Pd and Pt) are consistent with a structure containing a terminal hydride, especially when compared to the chemical shifts of related pincer-supported complexes. In fact, in this work, two general trends relating to the (1)H NMR chemical shifts of group 10 pincer-supported terminal hydrides were elucidated: (i) the hydride shift moves downfield from Ni to Pd to Pt and (ii) the hydride shift moves downfield with more trans-influencing pincer central donors. DFT calculations indicate that structures containing a M(II) hydride are lower in energy than the corresponding η(2)-silane isomers. Furthermore, the calculated NMR chemical shifts of the M(II) hydrides using a relativistic four-component methodology incorporating all significant scalar and spin-orbit corrections are consistent with those observed experimentally. Finally, in situ X-ray absorption spectroscopy (XAS) was used to provide further support that ((Cy)PSiP)MH exist as M(II) hydrides in solution.

5.
Angew Chem Int Ed Engl ; 53(4): 1103-8, 2014 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-24338980

RESUMO

Pd and Ni dimers supported by PSiP ligands in which two hypervalent five-coordinate Si atoms bridge the two metal centers are reported. Crystallographic characterization revealed a rare square-pyramidal geometry at Si and an unusual asymmetric M2 Si2 core (M=Pd or Ni). DFT calculations showed that the unusual structure of the core is also found in a model in which the phosphine and Si centers are not part of a pincer group, thus indicating that the observed geometry is not imposed by the PSiP ligand. NBO analysis showed that an asymmetric four-center two-electron (4c-2e) bond stabilizes the hypervalent Si atoms in the M2 Si2 core.

6.
Biomaterials ; 311: 122692, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38986360

RESUMO

Branching is a key structural parameter of polymers, which can have profound impacts on physicochemical properties. It has been demonstrated that branching is a modulating factor for mRNA delivery and transfection using delivery vehicles built from cationic polymers, but the influence of polymer branching on mRNA delivery remains relatively underexplored compared to other polymer features such as monomer composition, hydrophobicity, pKa, or the type of terminal group. In this study, we examined the impact of branching on the physicochemical properties of poly(amine-co-esters) (PACE) and their efficiency in mRNA transfection in vivo and in vitro under various conditions. PACE polymers were synthesized with various degrees of branching ranging from 0 to 0.66, and their transfection efficiency was systemically evaluated. We observed that branching improves the stability of polyplexes but reduces the pH buffering capacity. Therefore, the degree of branching (DB) must be optimized in a delivery route specific manner due to differences in challenges faced by polyplexes in different physiological compartments. Through a systematic analysis of physicochemical properties and mRNA transfection in vivo and in vitro, this study highlights the influence of polymer branching on nucleic acid delivery.


Assuntos
Poliaminas , RNA Mensageiro , Transfecção , Transfecção/métodos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Animais , Poliaminas/química , Humanos , Camundongos , Concentração de Íons de Hidrogênio , Ésteres/química , Polímeros/química
7.
Mol Cancer Ther ; 23(8): 1176-1187, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691846

RESUMO

The treatment of primary central nervous system tumors is challenging due to the blood-brain barrier and complex mutational profiles, which is associated with low survival rates. However, recent studies have identified common mutations in gliomas [isocitrate dehydrogenase (IDH)-wild-type and mutant, WHO grades II-IV; with grade IV tumors referred to as glioblastomas (GBM)]. These mutations drive epigenetic changes, leading to promoter methylation at the nicotinic acid phosphoribosyl transferase (NAPRT) gene locus, which encodes an enzyme involved in generating NAD+. Importantly, NAPRT silencing introduces a therapeutic vulnerability to inhibitors targeting another NAD+ biogenesis enzyme, nicotinamide phosphoribosyl transferase (NAMPT), rationalizing a treatment for these malignancies. Multiple systemically administered NAMPT inhibitors (NAMPTi) have been developed and tested in clinical trials, but dose-limiting toxicities-including bone marrow suppression and retinal toxicity-have limited their efficacy. Here, we report a novel approach for the treatment of NAPRT-silenced GBMs using nanoparticle (NP)-encapsulated NAMPTis administered by convection-enhanced delivery (CED). We demonstrate that GMX1778 (a NAMPTi) can be formulated in degradable polymer NPs with retention of potency for NAMPT inhibition and anticancer activity in vitro, plus sustained drug release in vitro and in vivo. Direct injection of these drugs via CED into the brain is associated with reduced retinal toxicity compared with systemic administration. Finally, we show that CED of NP-encapsulated GMX1778 to NAPRT-silenced intracranial GBM xenografts in mice exhibit significant tumor growth delay and extends survival. These data support an approach to treat gliomas harboring defects in NAD+ metabolism using CED of NP-encapsulated NAMPTis to greatly improve the therapeutic index and treatment efficacy for this class of drugs.


Assuntos
Glioma , Nanopartículas , Nicotinamida Fosforribosiltransferase , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Humanos , Animais , Camundongos , Nanopartículas/química , Glioma/tratamento farmacológico , Glioma/patologia , Citocinas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia
8.
Sci Transl Med ; 15(709): eabq0603, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37585505

RESUMO

An inhalable platform for messenger RNA (mRNA) therapeutics would enable minimally invasive and lung-targeted delivery for a host of pulmonary diseases. Development of lung-targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here, we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) (PACE) polyplexes for mRNA delivery using end-group modifications and polyethylene glycol. These polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for severe acute respiratory syndrome coronavirus 2 and found that intranasal vaccination with spike protein-encoding mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected susceptible mice from lethal viral challenge. Together, these results demonstrate the translational potential of PACE polyplexes for therapeutic delivery of mRNA to the lungs.


Assuntos
COVID-19 , Nanopartículas , Animais , Camundongos , Polímeros , RNA Mensageiro/genética , COVID-19/prevenção & controle , Pulmão , Vacinação
9.
Sci Adv ; 9(6): eabq7459, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36753549

RESUMO

Glioblastoma (GBM) is one of the most lethal malignancies with poor survival and high recurrence rates. Here, we aimed to simultaneously target oncomiRs 10b and 21, reported to drive GBM progression and invasiveness. We designed short (8-mer) γ-modified peptide nucleic acids (sγPNAs), targeting the seed region of oncomiRs 10b and 21. We entrapped these anti-miR sγPNAs in nanoparticles (NPs) formed from a block copolymer of poly(lactic acid) and hyperbranched polyglycerol (PLA-HPG). The surface of the NPs was functionalized with aldehydes to produce bioadhesive NPs (BNPs) with superior transfection efficiency and tropism for tumor cells. When combined with temozolomide, sγPNA BNPs administered via convection-enhanced delivery (CED) markedly increased the survival (>120 days) of two orthotopic (intracranial) mouse models of GBM. Hence, we established that BNPs loaded with anti-seed sγPNAs targeting multiple oncomiRs are a promising approach to improve the treatment of GBM, with a potential to personalize treatment based on tumor-specific oncomiRs.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Nanopartículas , Ácidos Nucleicos Peptídicos , Camundongos , Animais , Ácidos Nucleicos Peptídicos/farmacologia , Encéfalo/patologia , Glioblastoma/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Temozolomida , Linhagem Celular Tumoral
10.
Sci Transl Med ; 15(720): eadi1617, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37910601

RESUMO

The morbidity associated with pediatric medulloblastoma, in particular in patients who develop leptomeningeal metastases, remains high in the absence of effective therapies. Administration of substances directly into the cerebrospinal fluid (CSF) is one approach to circumvent the blood-brain barrier and focus delivery of drugs to the site of tumor. However, high rates of CSF turnover prevent adequate drug accumulation and lead to rapid systemic clearance and toxicity. Here, we show that PLA-HPG nanoparticles, made with a single-emulsion, solvent evaporation process, can encapsulate talazoparib, a PARP inhibitor (BMN-673). These degradable polymer nanoparticles improve the therapeutic index when delivered intrathecally and lead to sustained drug retention in the tumor as measured with PET imaging and fluorescence microscopy. We demonstrate that administration of these particles into the CSF, alone or in combination with systemically administered temozolomide, is a highly effective therapy for tumor regression and prevention of leptomeningeal spread in xenograft mouse models of medulloblastoma. These results provide a rationale for harnessing nanoparticles for the delivery of drugs limited by brain penetration and therapeutic index and demonstrate important advantages in tolerability and efficacy for encapsulated drugs delivered locoregionally.


Assuntos
Antineoplásicos , Neoplasias Cerebelares , Meduloblastoma , Nanopartículas , Criança , Humanos , Camundongos , Animais , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Meduloblastoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Neoplasias Cerebelares/tratamento farmacológico , Líquido Cefalorraquidiano
11.
Biomaterials ; 287: 121676, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35849999

RESUMO

Poly(ethylene glycol) (PEG) is widely employed for passivating nanoparticle (NP) surfaces to prolong blood circulation and enhance localization of NPs to target tissue. However, the immune response of PEGylated NPs-including anti-PEG antibody generation, accelerated blood clearance (ABC), and loss of delivery efficacy-is of some concern, especially for treatments that require repeat administrations. Although polyglycerol (PG), which has the same ethylene oxide backbone as PEG, has received attention as an alternative to PEG for NP coatings, the pharmacokinetic and immunogenic impact of PG has not been studied systematically. Here, linear PG, hyperbranched PG (hPG), and PEG-coated polylactide (PLA) NPs with varying surface densities were studied in parallel to determine the pharmacokinetics and immunogenicity of PG and hPG grafting, in comparison with PEG. We found that linear PG imparted the NPs a stealth property comparable to PEG, while hPG-grafted NPs needed a higher surface density to achieve the same pharmacokinetic impact. While linear PG-grafted NPs induced anti-PEG antibody production in mice, they exhibited minimal accelerated blood clearance (ABC) effects due to the poor interaction with anti-PEG immunoglobulin M (IgM). Further, we observed no anti-polymer IgM responses or ABC effects for hPG-grafted NPs.

12.
Nat Biotechnol ; 40(3): 325-334, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34711990

RESUMO

Gene amplification drives oncogenesis in a broad spectrum of cancers. A number of drugs have been developed to inhibit the protein products of amplified driver genes, but their clinical efficacy is often hampered by drug resistance. Here, we introduce a therapeutic strategy for targeting cancer-associated gene amplifications by activating the DNA damage response with triplex-forming oligonucleotides (TFOs), which drive the induction of apoptosis in tumors, whereas cells without amplifications process lower levels of DNA damage. Focusing on cancers driven by HER2 amplification, we find that TFOs targeting HER2 induce copy number-dependent DNA double-strand breaks (DSBs) and activate p53-independent apoptosis in HER2-positive cancer cells and human tumor xenografts via a mechanism that is independent of HER2 cellular function. This strategy has demonstrated in vivo efficacy comparable to that of current precision medicines and provided a feasible alternative to combat drug resistance in HER2-positive breast and ovarian cancer models. These findings offer a general strategy for targeting tumors with amplified genomic loci.


Assuntos
Neoplasias da Mama , Amplificação de Genes , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Dano ao DNA , Feminino , Genômica , Humanos , Oligonucleotídeos
13.
ACS Nano ; 15(10): 16118-16129, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34633171

RESUMO

Although poly(ethylene glycol) (PEG) is commonly used in nanoparticle design, the impact of surface topography on nanoparticle performance in biomedical applications has received little attention, despite showing significant promise in the study of inorganic nanoparticles. Control of the surface topography of polymeric nanoparticles is a formidable challenge due to the limited conformational control of linear polymers that form the nanoparticle surface. In this work, we establish a straightforward method to precisely tailor the surface topography of PEGylated polymeric nanoparticles based on tuning the architecture of shape-persistent amphiphilic bottlebrush block copolymer (BBCP) building blocks. We demonstrate that nanoparticle formation and surface topography can be controlled by systematically changing the structural parameters of BBCP architecture. Furthermore, we reveal that the surface topography of PEGylated nanoparticles significantly affects their performance. In particular, the adsorption of a model protein and the uptake into HeLa cells were closely correlated to surface roughness and BBCP terminal PEG block brush width. Overall, our work elucidates the importance of surface topography in nanoparticle research as well as provides an approach to improve the performance of PEGylated nanoparticles.


Assuntos
Nanopartículas , Polietilenoglicóis , Células HeLa , Humanos , Polímeros , Proteínas
14.
Biomaterials ; 201: 87-98, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30802686

RESUMO

Glioblastoma (GBM) is the most common and deadly form of malignant brain tumor in the United States, and current therapies fail to provide significant improvement in survival. Local delivery of nanoparticles is a promising therapeutic strategy that bypasses the blood-brain barrier, minimizes systemic toxicity, and enhances intracranial drug distribution and retention. Here, we developed nanoparticles loaded with agents that inhibit miR-21, an oncogenic microRNA (miRNA) that is strongly overexpressed in GBM compared to normal brain tissue. We synthesized, engineered, and characterized two different delivery systems. One was designed around an anti-miR-21 composed of RNA and employed a cationic poly(amine-co-ester) (PACE). The other was designed around an anti-miR-21 composed of peptide nucleic acid (PNA) and employed a block copolymer of poly(lactic acid) and hyperbranched polyglycerol (PLA-HPG). We show that both nanoparticle products facilitate efficient intracellular delivery and miR-21 suppression that leads to PTEN upregulation and apoptosis of human GBM cells. Further, when administered by convection-enhanced delivery (CED) to animals with intracranial gliomas, they both induced significant miR-21 knockdown and provided chemosensitization, resulting in improved survival when combined with chemotherapy. The challenges involved in optimizing the two delivery systems differed, and despite offering distinct advantages and limitations, results showed significant therapeutic efficacy with both methods of treatment. This study demonstrates the feasibility and promise of local administration of miR-21 inhibiting nanoparticles as an adjuvant therapy for GBM.


Assuntos
Glioblastoma/metabolismo , Glioblastoma/terapia , MicroRNAs/metabolismo , Nanopartículas/química , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Western Blotting , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Glicerol/química , Humanos , Masculino , MicroRNAs/genética , MicroRNAs/fisiologia , PTEN Fosfo-Hidrolase/metabolismo , Ácidos Nucleicos Peptídicos/química , Polímeros/química , Ratos
15.
Bioeng Transl Med ; 4(1): 129-140, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30680324

RESUMO

Conventional emulsion-based sunscreen formulations are limited by postapplication epicutaneous penetration that increases the risk of allergic dermatitis, cellular damage, and filter photodegradation upon ultraviolet radiation (UVR) exposure. Encapsulation of the UVB filter padimate O within bioadhesive biodegradable nanoparticles (BNPs) composed of poly(d,l-lactic acid)-hyperbranched polyglycerol was previously shown to enhance UVR protection while preventing skin absorption. Herein, we assess the capacity of BNP co-incorporation of avobenzone and octocrylene to provide broad-spectrum UVR protection. The ratio of UV filters within nanoparticles (NPs) was optimized for filter-filter stabilization upon UV irradiation and maximum drug loading. In vitro water-resistance test showed significant particle retention at 85% over 3 hr. In a pilot clinical study, protection against UVR-induced erythema of BNPs was found to be comparable to the FDA standard P2. Thus, sunscreen formulations utilizing BNP incorporation of a combination of organic filters may offer key safety and performance advantages.

16.
Nat Commun ; 8: 15322, 2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28524852

RESUMO

Nanoparticles are of long-standing interest for the treatment of neurological diseases such as glioblastoma. Most past work focused on methods to introduce nanoparticles into the brain, suggesting that reaching the brain interstitium will be sufficient to ensure therapeutic efficacy. However, optimized nanoparticle design for drug delivery to the central nervous system is limited by our understanding of their cellular deposition in the brain. Here, we investigated the cellular fate of poly(lactic acid) nanoparticles presenting different surface chemistries, after administration by convection-enhanced delivery. We demonstrate that nanoparticles with 'stealth' properties mostly avoid internalization by all cell types, but internalization can be enhanced by functionalization with bio-adhesive end-groups. We also show that association rates measured in cultured cells predict the extent of internalization of nanoparticles in cell populations. Finally, evaluating therapeutic efficacy in an orthotopic model of glioblastoma highlights the need to balance significant uptake without inducing adverse toxicity.


Assuntos
Encéfalo/metabolismo , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Ácido Poliglicólico/química , Animais , Encéfalo/efeitos dos fármacos , Neoplasias Encefálicas/terapia , Linhagem Celular , Linhagem Celular Tumoral , Sistema Nervoso Central/efeitos dos fármacos , Citometria de Fluxo , Glioblastoma/terapia , Glicerol/química , Cinética , Luz , Camundongos , Microglia/metabolismo , Polímeros/química , Ratos , Espalhamento de Radiação , Propriedades de Superfície
17.
Korean J Fam Med ; 33(6): 346-55, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23267420

RESUMO

BACKGROUND: Combined therapy with alendronate and calcitriol may have additive effects on bone density. An observational study was performed to evaluate the efficacy and safety of Maxmarvil, a combinative agent of alendronate (5 mg) and calcitriol (0.5 µg), and to identify factors associated with efficacy. METHODS: A total of 568 postmenopausal women with osteoporosis were enrolled by family physicians in 12 hospitals. The study subjects took Maxmarvil daily for 12 months. Questionnaires about baseline characteristics, socioeconomic status, and daily calcium intake were completed at the first visit. Adverse events were recorded every 3 months and bone mineral density (BMD) in the lumbar spine was measured using dual-energy X-ray absorptiometry at baseline and after 12 months. We evaluated the efficacy and safety of Maxmarvil, and the factors related to BMD improvement. RESULTS: A total of 370 patients were included in final analysis. The median BMD was 0.81 ± 0.12 g/cm(2) at pre-treatment and 0.84 ± 0.13 g/cm(2) after one year. The average BMD improvement was 3.4% ± 6.4% (P < 0.05), and 167 (45.1%) patients showed improvement. Factors associated with improved BMD were continuation of treatment (odds ratio [OR], 2.41; 95% confidence interval [CI], 1.15 to 5.07) and good compliance (OR, 2.54; 95% CI, 1.29 to 5.00). Adverse events were reported by 35 of the 568 patients, with the most common being abdominal pain and dyspepsia. CONCLUSION: Maxmarvil was found to be safe, well tolerated and effective in osteoporosis treatment. Continuation of treatment and good compliance were the factors associated with efficacy.

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