Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Front Reprod Health ; 5: 1210083, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37674657

RESUMO

Nowadays there are multiple types of contraceptive methods, from reversible to permanent, for those choosing to delay pregnancy. Misconceptions about contraception and infertility are a key factor for discontinuation or the uptake of family planning methods. Regaining fertility (the ability to conceive) after contraceptive discontinuation is therefore pivotal. Technical studies to date have evaluated return to fertility by assessing pregnancy as an outcome, with variable results, or return to ovulation as a surrogate measure by assessing hormone levels (such as progesterone, LH, FSH) with or without transvaginal ultrasound. In general, relying on time to pregnancy as an indicator of return to fertility following contraceptive method discontinuation can be problematic due to variable factors independent of contraceptive effects on fertility, hormone clearance, and fertility recovery. Since the ability to conceive after contraceptive method discontinuation is a critical factor influencing product uptake, it is important to have robust biomarkers that easily and accurately predict the timing of fertility return following contraception and isolate that recovery from extrinsic and circumstantial factors. The main aim of this review is to summarize the current approaches, existing knowledge, and gaps in methods of evaluating return-to-fertility as well as to provide insights into the potential of new biomarkers to more accurately predict fertility restoration after contraceptive discontinuation. Biomarker candidates proposed in this document include those associated with folliculogenesis, cumulus cell expansion, follicular rupture and ovulation, and endometrial transport and receptivity which have been selected and scored on predefined criteria meant to evaluate their probable viability for advancement. The review also describes limitations, regulatory requirements, and a potential path to clinically testing these selected biomarkers. It is important to understand fertility restoration after contraceptive method discontinuation to provide users and health providers with accurate evidence-based information. Predictive biomarkers, if easy and low-cost, have the potential to enable robust evaluation of RTF, and provide potential users the information they desire when selecting a contraceptive method. This could lead to expanded uptake and continuation of modern contraception and inform the development of new contraceptive methods to widen user's family planning choices.

2.
Eur J Contracept Reprod Health Care ; 27(2): 142-147, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34845964

RESUMO

OBJECTIVE: Increased research efforts over the past decade provide a more in-depth understanding of the diverse fertility desires and family planning needs of trans and gender diverse individuals assigned female at birth (TGD AFAB). Despite this increased understanding and unmet need, global health researchers and contraceptive product developers have yet to include TGD AFAB individuals and considerations of their needs in the product development process, marginalising this historically underrepresented population. The aim of this perspective is to present the case for inclusion of TGD AFAB individuals in contraceptive research. MAIN OUTCOMES: This perspective summarises the most recent literature characterising contraceptive access and use within TGD AFAB populations as well as the barriers to use. Furthermore, this perspective offers insight into how novel contraceptive technologies in the research and development pipeline could potentially appeal to TGD AFAB populations and recommends steps product developers can make towards being more inclusive. CONCLUSIONS: With current research efforts in contraceptive product development aimed at expanding the method mix to appeal to a more diverse population of potential users, it behoves product developers to be more inclusive of TGD AFAB individuals in the development process and consider them as stakeholders of an expanded contraceptive method mix.


Assuntos
Anticoncepção , Anticoncepcionais , Dispositivos Anticoncepcionais , Serviços de Planejamento Familiar , Feminino , Humanos , Recém-Nascido , Tecnologia
3.
J Int AIDS Soc ; 23(11): e25635, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33161636

RESUMO

INTRODUCTION: Learning one's HIV status through HIV testing services (HTS) is an essential step toward accessing treatment and linking to preventive services for those at high HIV risk. HTS may impact subsequent sexual behaviour, but the degree to which this varies by population or is true in the setting of contemporary HIV prevention activities is largely unknown. As part of the 2019 World Health Organization Consolidated Guidelines on HTS, we undertook a systematic review and meta-analysis to determine the effect of HTS on sexual behaviour. METHODS: We searched nine electronic databases for studies published between July 2010 and December 2019. We included studies that reported on at least one outcome (condom use [defined as the frequency of condom use or condom-protected sex], number of sex partners, HIV incidence, STI incidence/prevalence). We included studies that prospectively assessed outcomes and that fit into one of three categories: (1) those evaluating more versus less-intensive HTS, (2) those of populations receiving HTS versus not and (3) those evaluating outcomes after versus before HTS. We conducted meta-analyses using random-effects models. RESULTS AND DISCUSSION: Of 29 980 studies screened, 76 studies were included. Thirty-eight studies were randomized controlled trials, 36 were cohort studies, one was quasi-experimental and one was a serial cross-sectional study. There was no significant difference in condom use among individuals receiving more-intensive HTS compared to less-intensive HTS (relative risk [RR]=1.03; 95% CI: 0.99 to 1.07). Condom use was significantly higher after receiving HTS compared to before HTS for individuals newly diagnosed with HIV (RR = 1.65; 95% CI: 1.36 to 1.99) and marginally significantly higher for individuals receiving an HIV-negative diagnosis (RR = 1.63; 95% CI: 1.01 to 2.62). Individuals receiving more-intensive HTS reported fewer sex partners at follow-up than those receiving less-intensive HTS, but the finding was not statistically significant (mean difference = -0.28; 95% CI: -3.66, 3.10). CONCLUSIONS: Our findings highlight the importance of using limited resources towards HTS strategies that focus on early HIV diagnosis, treatment and prevention services rather than resources dedicated to supplementing or enhancing HTS with additional counselling or other interventions.


Assuntos
Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Teste de HIV , Sexo Seguro , Comportamento Sexual , Preservativos , Aconselhamento , Feminino , Humanos , Masculino , Comportamento de Redução do Risco , Parceiros Sexuais
4.
Euro Surveill ; 24(48)2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31796157

RESUMO

The 2019 online pre-exposure prophylaxis (PrEP) user survey in the United Kingdom was conducted to assess HIV PrEP access, and user characteristics. One in five respondents continued experiencing difficulties accessing PrEP; users were almost exclusively gay or bisexual men at high risk of HIV. The majority obtained PrEP through health service clinics and rated PrEP positively. High STI rates were reported among users. Renal and sexual health checks are advised for those sourcing PrEP privately.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/prevenção & controle , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Profilaxia Pré-Exposição/métodos , Adulto , Fármacos Anti-HIV/provisão & distribuição , Bissexualidade , Estudos Transversais , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Comportamento Sexual , Inquéritos e Questionários , Reino Unido
5.
Invest Ophthalmol Vis Sci ; 60(5): 1696-1705, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31009525

RESUMO

Purpose: The goal of this work was to design and assess the ability of unmodified and surface-modified poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) to enhance cell association, provide efficacy in retinoblastoma cells, and overcome current administration challenges, including hydrolysis and precipitation, of intravitreal administration. Methods: A single emulsion method was used to encapsulate Coumarin 6, to enable NP visualization via fluorescence microscopy. Melphalan NPs were synthesized using an adapted double-emulsion method to reduce melphalan loss during fabrication. Melphalan loading and release were quantified against a free melphalan standard. The cellular association and internalization of unmodified and surface-modified NPs were determined using flow cytometry, and the efficacy of melphalan NPs was quantified in retinoblastoma cells. Results: The highest cell association was observed with TET1 and MPG-NPs after 24 hours administration; however, a significant fraction of NPs were associated with the cell surface, instead of undergoing internalization. MPG-NPs fabricated with the low saturation process were most efficacious, while all surface-modified NPs improved efficacy relative to unmodified NPs when formulated using the highly saturated process. Similar effects were observed as a function of NP dose, with TET1 and MPG-NPs particularly efficacious. Conclusions: Surface-modified NPs achieved enhanced association and efficacy in retinoblastoma cells relative to unmodified NPs, with MPG and surface-modified NPs exhibiting the strongest efficacy relative to other NP groups. In future work we seek to assess the ability of these NPs to improve transport in the vitreous, where we expect a more dramatic impact on efficacy as a function of surface modification.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Sistemas de Liberação de Medicamentos , Melfalan/administração & dosagem , Nanopartículas/química , Neoplasias da Retina/tratamento farmacológico , Retinoblastoma/tratamento farmacológico , Cumarínicos/química , Citometria de Fluxo , Humanos , Injeções Intravítreas , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Tiazóis/química , Células Tumorais Cultivadas
6.
Pharm Res ; 36(5): 66, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30868271

RESUMO

PURPOSE: Hypovascularization of cervical tumors, coupled with intrinsic and acquired drug resistance, has contributed to marginal therapeutic outcomes by hindering chemotherapeutic transport and efficacy. Recently, the heterogeneous penetration and distribution of cell penetrating peptide (CPP, here MPG) and polyethylene glycol (PEG) modified poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were evaluated as a function of tumor type and morphology in cervical cancer spheroids modeling hypovascularized tumor nodules. Building upon this work, this study investigates the efficacy imparted by surface-modified Doxorubicin-loaded NPs transported into hypovascularized tissue. METHODS: NP efficacy was measured in HeLa, CaSki, and SiHa cells. NP internalization and association, and associated cell viability, were determined in monolayer and spheroid models. RESULTS: MPG and PEG-NP co-treatment was most efficacious in HeLa cells, while PEG NPs were most efficacious in CaSki cells. NP surface-modifications were unable to improve efficacy, relative to unmodified NPs, in SiHa cells. CONCLUSIONS: The results highlight the dependence of efficacy on tumor type and the associated microenvironment. The results further relate previous NP transport studies to efficacy, as a function of surface-modification and cell type. Longer-term, this information may help guide the design of NP-mediated strategies to maximize efficacy based on patient-specific cervical tumor origin and characteristics.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Peptídeos Penetradores de Células/metabolismo , Doxorrubicina/administração & dosagem , Portadores de Fármacos/metabolismo , Nanopartículas/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/química , Colo do Útero/irrigação sanguínea , Colo do Útero/efeitos dos fármacos , Colo do Útero/metabolismo , Colo do Útero/patologia , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Feminino , Células HeLa , Humanos , Nanopartículas/química , Polietilenoglicóis/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/metabolismo , Neoplasias do Colo do Útero/irrigação sanguínea , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia
7.
Eur J Pharm Biopharm ; 138: 37-47, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30195726

RESUMO

The secreted mucus layer in the vaginal epithelium presents a formidable barrier to the transport of active agents for the prevention and treatment of female reproductive tract (FRT) infections. Nanoparticle-mediated drug delivery has been proposed to help facilitate the transport and release of active agents through the cervicovaginal mucus (CVM) and underlying mucosa. However, both nanoparticles (NPs) and free active agents face a variety of challenges, often requiring the administration of high localized doses to circumvent leakage and poor penetration to targeted intravaginal tissue compartments. To address these challenges, "stealth" NP modifications have been investigated, due to their favorable mucus-penetrating properties, resulting in improved intravaginal active agent retention and transport. A number of other NP characteristics including size, surface modification type, ligand density, and co-modification, as well as the complexity of the FRT tissue are involved in obtaining adequate tissue penetration and, if needed, cell internalization. Studies that systematically investigate variations of these characteristics have yet to be conducted, with the goal to obtain a better understanding of what properties most impact prophylactic and therapeutic benefit. To complement the progress made with experimental evaluation of active agent transport in in vitro and in vivo, mathematical modeling has recently been applied to analyze the transport performance of agents and delivery vehicles in the FRT. Here, we build upon this work to simulate NP transport through mucus gel, epithelial, and stromal compartments, with the goal to provide a platform that can systematically evaluate transport based on NP and tissue characteristics. Model parameters such as PEG density and NP release (decay) rate from mucus gel into the epithelium, are set from previous in vitro and in vivo experimental work that assessed the transport of poly(lactic-co-glycolic acid (PLGA) NPs. The modeling results show that while unmodified and 2% PEG-modified NPs were retained in mucus for ∼1-4 h, dependent upon decay constant values, and traverse to the epithelium, no NP penetration was observed in the stroma. In contrast, NPs modified with 3% PEG, exhibited prolonged retention in each compartment, remaining for ∼4-6 h. Moreover, a significant concentration of NPs is observed in the stroma, indicating a transition in transport behavior. For NPs modified with 5, 8, or 25% PEG, steady retention profiles were noted, which gradually decline over 24 h. To supplement this modeling study and to develop a more representative experimental system that may be useful in future work, we report on the feasibility of constructing single and multicellular layered (MCL) culture systems to represent the epithelial and stromal tissue of the FRT. We anticipate that a combined mathematical/experimental approach may longer term enable prediction and customization of patient tissue-specific approaches to attain effective NP-mediated drug delivery and release for the treatment of infectious disease.


Assuntos
Doenças Transmissíveis/tratamento farmacológico , Genitália Feminina/efeitos dos fármacos , Nanopartículas/administração & dosagem , Infecções do Sistema Genital/tratamento farmacológico , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Muco/efeitos dos fármacos , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química
8.
Int J Nanomedicine ; 13: 2709-2727, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29760551

RESUMO

A variety of drug-delivery platforms have been employed to deliver therapeutic agents across cervicovaginal mucus (CVM) and the vaginal mucosa, offering the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract (FRT). Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, polymeric NPs represent a promising option that has shown improved distribution through the CVM. These NPs are typically fabricated from nontoxic, non-inflammatory, US Food and Drug Administration-approved polymers that improve biocompatibility. This review summarizes recent experimental studies that have evaluated NP transport in the FRT, and highlights research areas that more thoroughly and efficiently inform polymeric NP design, including mathematical modeling. An overview of the in vitro, ex vivo, and in vivo NP studies conducted to date - whereby transport parameters are determined, extrapolated, and validated - is presented first. The impact of different NP design features on transport through the FRT is summarized, and gaps that exist due to the limitations of iterative experimentation alone are identified. The potential of mathematical modeling to complement the characterization and evaluation of diffusion and transport of delivery vehicles and active agents through the CVM and mucosa is discussed. Lastly, potential advancements combining experimental and mathematical knowledge are suggested to inform next-generation NP designs, such that infections in the FRT may be more effectively treated.


Assuntos
Anti-Infecciosos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Nanopartículas/química , Infecções do Sistema Genital/tratamento farmacológico , Animais , Anti-Infecciosos/farmacocinética , Muco do Colo Uterino/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Humanos , Modelos Teóricos , Polímeros/química , Vagina/efeitos dos fármacos
9.
J Nanobiotechnology ; 15(1): 67, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28982361

RESUMO

BACKGROUND: Advanced stage cancer treatments are often invasive and painful-typically comprised of surgery, chemotherapy, and/or radiation treatment. Low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies. To address these transport challenges, nanoparticles (NPs) are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. Here, we evaluate stealth polyethylene-glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies in 3D cell culture representing hypo-vascularized tissue. RESULTS: Smaller, more regularly-shaped avascular tissue was generated using the hanging drop (HD) method, while more irregularly-shaped masses were formed with the liquid overlay (LO) technique. To compare NP distribution differences within the same type of tissue as a function of different cancer types, we selected HeLa, cervical epithelial adenocarcinoma cells; CaSki, cervical epidermoid carcinoma cells; and SiHa, grade II cervical squamous cell carcinoma cells. In HD tumors, enhanced distribution relative to unmodified NPs was measured for MPG and PEG NPs in HeLa, and for all modified NPs in SiHa spheroids. In LO tumors, the greatest distribution was observed for MPG and MPG/PEG NPs in HeLa, and for PEG and MPG/PEG NPs in SiHa spheroids. CONCLUSIONS: Pre-clinical evaluation of PLGA-modified NP distribution into hypo-vascularized tumor tissue may benefit from considering tissue morphology in addition to cancer type.


Assuntos
Portadores de Fármacos/metabolismo , Ácido Láctico/metabolismo , Nanopartículas/metabolismo , Neoplasias/irrigação sanguínea , Polietilenoglicóis/metabolismo , Ácido Poliglicólico/metabolismo , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , Portadores de Fármacos/análise , Células HeLa , Humanos , Ácido Láctico/análise , Nanopartículas/análise , Neoplasias/metabolismo , Polietilenoglicóis/análise , Ácido Poliglicólico/análise , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Esferoides Celulares , Células Tumorais Cultivadas
10.
Int J Pharm ; 531(1): 118-133, 2017 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-28797967

RESUMO

Sexually transmitted infections affect hundreds of millions of people worldwide. Both human immunodeficiency virus (HIV-1 and -2) and herpes simplex virus-2 (HSV-2) remain incurable, urging the development of new prevention strategies. While current prophylactic technologies are dependent on strict user adherence to achieve efficacy, there is a dearth of delivery vehicles that provide discreet and convenient administration, combined with prolonged-delivery of active agents. To address these needs, we created electrospun fibers (EFs) comprised of FDA-approved polymers, poly(lactic-co-glycolic acid) (PLGA) and poly(DL-lactide-co-ε-caprolactone) (PLCL), to provide sustained-release and in vitro protection against HIV-1 and HSV-2. PLGA and PLCL EFs, incorporating the antiretroviral, tenofovir disoproxil fumarate (TDF), exhibited sustained-release for up to 4 weeks, and provided complete in vitro protection against HSV-2 and HIV-1 for 24h and 1 wk, respectively, based on the doses tested. In vitro cell culture and EpiVaginal tissue tests confirmed the safety of fibers in vaginal and cervical cells, highlighting the potential of PLGA and PLCL EFs as multipurpose next-generation drug delivery vehicles.


Assuntos
Fármacos Anti-HIV/farmacologia , Antivirais/farmacologia , Portadores de Fármacos/química , HIV-1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Tenofovir/farmacologia , Linhagem Celular , Colo do Útero/citologia , Feminino , Humanos , Ácido Láctico/química , Poliésteres/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Vagina/citologia
11.
Mater Sci Eng C Mater Biol Appl ; 72: 238-251, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28024582

RESUMO

More diverse multipurpose prevention technologies are urgently needed to provide localized, topical pre-exposure prophylaxis against sexually transmitted infections (STIs). In this work, we established the foundation for a multipurpose platform, in the form of polymeric electrospun fibers (EFs), to physicochemically treat herpes simplex virus 2 (HSV-2) infection. To initiate this study, we fabricated different formulations of poly(lactic-co-glycolic acid) (PLGA) and poly(dl-lactide-co-ε-caprolactone) (PLCL) EFs that encapsulate Acyclovir (ACV), to treat HSV-2 infection in vitro. Our goals were to assess the release and efficacy differences provided by these two different biodegradable polymers, and to determine how differing concentrations of ACV affected fiber efficacy against HSV-2 infection and the safety of each platform in vitro. Each formulation of PLGA and PLCL EFs exhibited high encapsulation efficiency of ACV, sustained-delivery of ACV through one month, and in vitro biocompatibility at the highest doses of EFs tested. Additionally, all EF formulations provided complete and efficacious protection against HSV-2 infection in vitro, regardless of the timeframe of collected fiber eluates tested. This work demonstrates the potential for PLGA and PLCL EFs as delivery platforms against HSV-2, and indicates that these delivery vehicles may be expanded upon to provide protection against other sexually transmitted infections.


Assuntos
Portadores de Fármacos/química , Herpesvirus Humano 2/fisiologia , Ácido Láctico/química , Poliésteres/química , Ácido Poliglicólico/química , Aciclovir/química , Aciclovir/farmacologia , Animais , Antivirais/química , Antivirais/farmacologia , Chlorocebus aethiops , Módulo de Elasticidade , Condutividade Elétrica , Microscopia Eletrônica de Varredura , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Células Vero , Internalização do Vírus/efeitos dos fármacos , Viscosidade
12.
Antimicrob Agents Chemother ; 60(11): 6518-6531, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27550363

RESUMO

Despite current prophylactic strategies, sexually transmitted infections (STIs) remain significant contributors to global health challenges, spurring the development of new multipurpose delivery technologies to protect individuals from and treat virus infections. However, there are few methods currently available to prevent and no method to date that cures human immunodeficiency virus (HIV) infection or combinations of STIs. While current oral and topical preexposure prophylaxes have protected against HIV infection, they have primarily relied on antiretrovirals (ARVs) to inhibit infection. Yet continued challenges with ARVs include user adherence to daily treatment regimens and the potential toxicity and antiviral resistance associated with chronic use. The integration of new biological agents may avert some of these adverse effects while also providing new mechanisms to prevent infection. Of the biologic-based antivirals, griffithsin (GRFT) has demonstrated potent inhibition of HIV-1 (and a multitude of other viruses) by adhering to and inactivating HIV-1 immediately upon contact. In parallel with the development of GRFT, electrospun fibers (EFs) have emerged as a promising platform for the delivery of agents active against HIV infection. In the study described here, our goal was to extend the mechanistic diversity of active agents and electrospun fibers by incorporating the biologic GRFT on the EF surface rather than within the EFs to inactivate HIV prior to cellular entry. We fabricated and characterized GRFT-modified EFs (GRFT-EFs) with different surface modification densities of GRFT and demonstrated their safety and efficacy against HIV-1 infection in vitro We believe that EFs are a unique platform that may be enhanced by incorporation of additional antiviral agents to prevent STIs via multiple mechanisms.


Assuntos
Proteínas de Algas/farmacologia , Antivirais/farmacologia , Sistemas de Liberação de Medicamentos/métodos , HIV-1/efeitos dos fármacos , Ácido Láctico/química , Lectinas de Plantas/farmacologia , Ácido Poliglicólico/química , Ligação Viral/efeitos dos fármacos , Proteínas de Algas/química , Antivirais/química , Linhagem Celular Transformada , Colo do Útero/citologia , Técnicas Eletroquímicas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Expressão Gênica , Genes Reporter , Células HeLa , Humanos , Luciferases/genética , Luciferases/metabolismo , Microscopia Eletrônica de Varredura , Lectinas de Plantas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Vagina/citologia , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
13.
J Nanobiotechnology ; 14: 33, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-27102372

RESUMO

BACKGROUND: Uncoordinated cellular proliferation and dysregulated angiogenesis in solid tumors are coupled with inadequate tissue, blood, and lymphatic vascularization. Consequently, tumors are often characterized by hypoxic regions with limited access to vascular-borne substances. In particular, systemically administered nanoparticles (NPs) targeting tumor cells and relying on vascular access to reach tumor tissue can suffer from limited therapeutic efficacy due to inhomogeneous intra-tumor distribution and insufficient cellular internalization of NPs. To circumvent these challenges, NP surfaces can be modified to facilitate tumor interstitial transport and cellular uptake. RESULTS: We create poly(lactic-co-glycolic) acid NPs modified with MPG, polyethylene glycol (PEG), MPG/PEG, and Vimentin (VIM), and evaluate their cellular uptake in 2D (monolayer) cell culture of human cervical carcinoma (HeLa). We compare NP performance by evaluating uptake by non-cancerous vaginal (VK2) cells. We further assess NP interstitial transport in hypo-vascularized lesions by evaluating the effect of the various modifications on NP penetration in 3D cell culture of the HeLa cells. Results show that after 24 h incubation with HeLa cells in monolayer, MPG, MPG/PEG, PEG, and VIM NPs were internalized at 66×, 24×, 30×, and 15× that of unmodified NPs, respectively. In contrast, incubation with VK2 cells in monolayer showed that MPG , MPG/PEG , PEG , and VIM NPs internalized at 6.3×, 4.3×, 12.4×, and 3.0× that of unmodified NPs, respectively. Uptake was significantly enhanced in tumorigenic vs. normal cells, with internalization of MPG NPs by HeLa cells being twice that of PEG NPs by VK2 cells. After 24 h incubation in HeLa 3D cell culture, MPG and MPG/PEGNPs were internalized 2× and 3× compared to PEG and VIM NPs, respectively. Whereas MPG NPs were internalized mostly in the cell culture periphery (1.2×, 1.4×, and 2.7× that of PEG, MPG/PEG, and VIM NPs, respectively), PEG NPs at 250 µm penetrated 2× farther into the tissue culture than MPG NPs. For all NP types, cellular internalization was severely hindered in 3D compared to monolayer. CONCLUSIONS: Although MPG surface modification enhances internalization and uptake in hypo-vascularized cervical tissue culture, coating with PEG reduces this internalization while enhancing penetration. A delivery strategy combining NPs with either modification may balance cellular internalization vs. tissue penetration in hypo-vascularized cervical cancer lesions.


Assuntos
Ácido Láctico/administração & dosagem , Nanopartículas/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Neoplasias do Colo do Útero/tratamento farmacológico , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Feminino , Células HeLa , Humanos , Tamanho da Partícula , Polietilenoglicóis/administração & dosagem , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...