Name: preparation and characterization of individual and multi-drug loaded physically entrapped polymeric micelles
Uploaded: 2015-08-28T13:00:00.000+00:00
Duration: 7 min 32 s
Description: Watch this Scientific Journal Video about Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles at JoVE.com

This study was supported by the grant from AACP New Pharmacy Faculty Research Award Program, Medical Research Foundation of Oregon New Investigator Grant, Oregon State University-Startup fund, and Pacific University, School of Pharmacy Start-up fund.

용매 주조 방법으로 개인 및 다중 약물로드 미셀 1. 준비 <ol><li> 이중 약물 미셀 1 mg의 각 (DDM)에서 DTX 1 mg의 또는 EVR 1 mg의 또는 두 약물을 달다. </li><li> PEG 2000 년의 15 밀리그램을 달아 - -PLA 1800 또는 PEG 4000 브렉퍼스트 - B -PLA 2200 개인 또는 DDM 중 하나를 위해. </li><li> 약물 / 마약과 5 ml의 둥근 바닥 플라스크에 아세토 니트릴과 장소의 0.5 ml의에서 폴리머를 용해. </li><li> 회전 증발기를 사용하여 감압하에 약물 (들) -polymer 아세토 니트릴 용액을 증발시켜 얇은 약물 분산 폴리머 필름을 형성한다. 100 RPM, 40 O C의 수조 온도 및 3 분 이상 100 밀리바에 이어 환원 5 분 동안 260 밀리바의 진공 압력을 회전 증발기를 설정한다. </li><li> O 50 ℃에서 탈 이온수 0.5ml를 가진 약물 - 고분자 필름을 재수 부드럽게 미셀을 형성하기 위해 플라스크를 흔들어. </li><li> 결과 필터0.2 ㎛의 나일론 필터를 통해 미셀 용액을 보내고하는 1.5 mL의 원심 분리 튜브에 어떠한 미용 약물 또는 오염물을 제거한다. </li></ol> 역상 고성능 액체 크로마토 그래피 (RP-HPLC)를 사용하여 평가 마이셀에서 약로드 및 안정성 2. <ol><li> 1 ml / 분의 유속으로 이동 아세토 니트릴 / 물 상 (38분의 62)를 함유하는 0.1 % 인산 1 % 메탄올로 등용 모드에서 40 ° C로 평형화 C8 컬럼으로 RP-HPLC 분석을 수행하고 10 μL의 주입량. </li><li> 이전의 초기 약물 부하를 결정하기 위해 RP-HPLC로 분석을 이동상 100 : 갓 준비 미셀 (섹션 1) (1)를 희석. RP-HPLC로 다시 평가하고 24 시간 이상 미셀 약물 (들)의 안정성을 결정하기 위해 이동상 100 희석 샘플 : 스토어 희석 ​​개인 미셀 48 시간 동안 실온 (25 O를 C)에서 DDM과 신선한 1을 준비합니다. </li><li> 각각 227, 279 nm에서 DTX와 EVR 피크를 모니터각각 1.7과 5.7 분의 체류 시간에. 세중에서 모든 측정을 수행합니다. 평균 ± SD 약물 로딩 중 현재 데이터. </li></ol> 동적 광산란에 의한 미셀 입자 크기 3. 평가 (DLS) <ol><li> 1.5 ㎎ / ㎖의 최종 중합체 농도를 수득 1:20의 비율로 탈 이온수 (제 1 항에서 설명)을 새로 제조 된 미셀을 희석. </li><li> 산란을 결정하기 위해 173 ℃에서 HE-Ne 레이저 (633 ㎚)의 강도를 측정한다. 2 분 전 평형 다음 25 ℃에서 모든 측정을 수행합니다. </li><li> 세중에서 모든 측정을 수행합니다. 분포의 분산 지수 (PDI)와 함께 ± 표준 편차 평균 Z 평균 크기와 같은 현재 데이터. </li></ol> 개인 미셀 DDM 4. 평가에서의 생체 외 약물 방출 <ol><li> 3 ㎖ 투석 카세트에 부 (1) 부하의 미셀의 2.5 ml에 설명 된대로 개별 미셀과 DDM 준비7,000g / 몰의 분자량 컷 오프 (MWCO). 주 :이 MWCO는 카세트 밖으로 자유롭게 확산시켜 싱크 조건을 보장하기 위해, 비 결합 된 중합체 분자와 함께 유리 약물 (들)를 활성화하기 위해 선택되었다. </li><li> (주 200 mM의 솔루션을 희석하여 제조) 10 mM의 pH 7.4의 인산염 완충액 2.5 L에 카세트를 놓고 싱크 조건을 보장하기 위해 버퍼마다 3 시간을 변경합니다. 실험 기간에 걸쳐 37 ℃에서 O 버퍼의 온도를 유지한다. </li><li> 에서 0, 0.5, 1, 2, 3, 6, 9, 12, 24, 48 시간, 카세트의 용액을 150 μL를 철회하고 신선한 완충액 150 μL로 교체한다. </li><li> 약물 농도를 결정하는 섹션 2 년에 설립으로 RP-HPLC를 사용하여 샘​​플을 분석 할 수 있습니다. stastitical 소프트웨어를 사용하여 하나의 위상 지수 협회 간단한 확산 모델에 기초한 약물은 분리 된 데이터를 곡선 - 적합. </li><li> E의 약물 방출의 50 %에 도달하는데 필요한 시간을 계산 (t 1/2)피팅 곡선을 기준으로 개별 미셀 또는 DDM에 ACH 약물. 네개에서 모든 측정을 수행합니다. </li></ol>

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The authors have nothing to disclose.

The use of polymeric micelles for drug delivery continues to expand due to their versatility and ability to deliver hydrophobic drugs for various disease states. Therefore, the techniques needed to prepare and characterize these formulations prior to use in cell culture or animals is a critical first step to determine the best pairing between the drug and the polymer. PEG-b-PLA are excellent amphiphilic block copolymers for drug delivery purposes. However, the block length of the hydrophilic and hydrophobic s...

친수성과 소수성 도메인으로 이루어지는 반복 구조로 양친 성 블록 공중 합체는 자발적으로 알려진 고분자 미셀 삼차원 고분자 조립체를 형성하기 위해 자기 조립있다. 이러한 구조는 친수성 ​​껍질로 둘러싸인 내부 소수성 코어를 가지고있다. 소수성 코어의 물리적 포획함으로써 소수성 상호 작용을 통해 또는 중합체 백본에 화학적 결합에 의해 하나의 소수성 약물을 포함하는 기능을 갖는다. (1) 많은 장점은 약물 전달을위한 미셀을 형성하기 위해 이러한 블록 공중 합체를 사용하기 위해 존재한다. 이들은 중합체의 난 용성 약물의 혼입, 혼입 약물 약동학을 개선하고 생체 적합성 및 / 또는 생분해 성을 포함하는 그들에게 종래의 가용 화제에 안전한 대체한다. (2) 고분자 미셀을 사용하는 또 다른 이점은 15을 사이에, 그 콜로이드 성 입자 크기 인 PA에 대한 그들에게 매력적 150 nm의 3,renteral 배달. 따라서, 지난 20 년 동안 고분자 미셀은 특히 암 치료에 대한 난 용성 약물 가능한 약물 전달 시스템으로서 등장했다. 3,4 마지막으로 폴리에틸렌 옥사이드를 함유하는 삼 블록 공중 합체 중에 현재 임상 시험을 진행 암 치료. 임상 시험에서 미셀의 4 개의 다섯 고분자 미셀 조성물은 PEG 계 블록 공중 합체가되어있다. 미셀의 크기는 20 nm 내지 85 nm의 변화. PEG 기재 중합체를 사용하는 장점은 생체 적합성이고, 제 2 블록도에 따라 생분해 될 수있다. polyethyleneglycol- 블록 -polylactic 산 (-PLA PEG- B) 고분자 미셀에 기초하여 최근 새로운 약물 전달 시스템은 다수의 항암제의 동시 전달을 위해 개발되어왔다. PEG-B-PLA 미셀은 생체 적합성과 생분해 성을 모두 있습니다. 로드 미셀로 도시 한이 다제ynergistic 시험 관내 및 생체 내에서 상이한 2,5,6 암 모델 저항의 억제 및 방지하기 위해 화학 요법에서 여러 약물을 이용하고 독성을 저하 현재 패러다임에 맞게. 따라서, 준비하고 암과 다른 질병 상태에서 사용하기 위해 이러한 미셀 약물 전달 시스템의 특성에 많은 관심이있다. 연구에서 우리는 미셀 조제와 명소 질환 상태에서 그 특징을 평가하기 전에 될 수있는 단계적인 프로세스를 이하에 설명했다. 이 연구의 목적으로 두 저조한 수용성 항암제는, 도세탁셀 (DTX)과 에베로 리무스 (EVR)가 선택되었다. DTX와 EVR 모두 각각 ㎖ / 1.9 및 9.6 μg의에서 극한 물 용해도와 난 용성 화합물이다. 다른 분자량을 가진 7,8- 두 PEG- ㄴ -PLA 중합체 제형 중합체위한 빌딩 블록으로서이 프로토콜에 사용 된 미셀,-PLA 1800 (3800 다) 및 PEG 4000 B - - -PLA 2200 (6200 다) (B)이 폴리머는 PEG 2000입니다. PEG-B의 -PLA 미셀 따라서 DTX와 EVR 개별적으로 조합에 대한 nanocarrier 같은 독특한 플랫폼을 제공 할 수 있습니다. 필요한 시약 / 재료 및 장비 준비와 이러한 미셀은 표 1에 나열된 특성을 필요로했다.

<table><tbody><tr><td>PEG2000-b-PLA1800</td><td>Advanced Polymer Materials, Inc</td><td>6-01- PLA/2000</td><td>PLA MW can be specified on ordering</td></tr><tr><td>PEG4000-b-PLA2200</td><td>Advanced Polymer Materials, Inc</td><td>6-01- PLA/4000</td><td>PLA MW can be specified on ordering</td></tr><tr><td>Docetaxel</td><td>LC Laboratories</td><td>D-1000</td><td>100 mg</td></tr><tr><td>Everolimus</td><td>LC Laboratories</td><td>E-4040</td><td>100 mg</td></tr><tr><td>Acetonitrile</td><td>EMD/VWR</td><td>EM-AX0145-1</td><td>HPLC grade; 4 L</td></tr><tr><td>Round bottom flask&amp;nbsp;</td><td>Glassco/VWR</td><td>89426-496</td><td>5 ml</td></tr><tr><td>RV 10 Control Rotary Evaporators</td><td>IKA Works</td><td>8025001</td><td>Rotoevaporator</td></tr><tr><td>Shimadzhu HPLC with DAD detector</td><td>Shimadzhu</td><td></td><td>RP-HPLC</td></tr><tr><td>Slide-a-lyzer dialysis casette MWCO 7000</td><td>Thermo Scientific, Inc</td><td>66370</td><td>3 ml</td></tr><tr><td>Phosphate buffer pH 7.4, 200 mM</td><td>VWR</td><td>100190-870</td><td>500 ml</td></tr><tr><td>Malvern NanoZS</td><td>Malvern Instruments, UK</td><td></td><td>DLS</td></tr><tr><td>Nylon filter</td><td>Acrodisc/VWR</td><td>28143-242</td><td>13 mm; 0.2&amp;micro;M</td></tr><tr><td>Phosphoric acid, NF</td><td>Spectrum Chemical/VWR</td><td>700000-626</td><td>100 ml</td></tr><tr><td>GraphPad Prism</td><td>&lt;a href=&quot;http://www.graphpad.com/&quot;&gt;www.graphpad.com&lt;/a&gt;</td><td></td><td>Analysis software</td></tr><tr><td>Zorbax SB-C8 Rapid Resolution cartridge&amp;nbsp;</td><td>Agilent Technologies</td><td>866953-906</td><td>4.6 &amp;times;75 mm, 3.5 &amp;#956;m</td></tr></tbody></table>

preparation and characterization of individual and multi-drug loaded physically entrapped polymeric micelles

polyethyleneglycol- 블록 -polylactic 아세트산 (PLA B- PEG-) 같은 양친 성 블록 공중 합체는 수성 환경에서 친수성, 소수성 쉘에 의해 둘러싸인 코어를 형성하는 자신의 임계 미셀 농도는 상기 미셀로 자기 조립할 수있다. 미셀의 코어는 도세탁셀 (DTX)과 에베로 리무스 (EVR)과 같은 소수성, 수난 용성 약물을로드하는데 이용 될 수있다. 미셀 구조 및 약물 로딩 기능의 체계적인 특성화 수행 할 수 시험관 및 생체 내 연구에서 이전에 중요하다. 본원에 기술 된 프로토콜의 목적은 표준화 미셀 제품을 달성하기 위해 필요한 특성을 제공하는 단계이다. DTX와 EVR 각각 미셀의 제조는 각각 1.86 및 1.85 ㎎ / ㎖에 DTX 및 EVR의 용해도를 증가 용매 캐스팅을 통해 달성 될 수있다 ㎖ / 1.9 및 9.6 μg의 극한의 용해도를 갖는다. 평가 미셀의 의약품 안정성48 시간 동안 실온에서 uated은 약물의 97 % 이상이 솔루션에 유지하고 있음을 나타냅니다. 미셀의 크기는 동적 광 산란을 사용하여 평가하고 이러한 미셀의 크기는 50 나노 미터 이하이고, 중합체의 분자량에 의존하고 있음을 나타내었다. 미셀에서 약물 방출은 48 시간에 걸쳐 37 O C에서의 pH 7.4에서 싱크 조건에서 투석을 사용하여 평가 하였다. 커브 피팅 결과는 약물 방출이 확산이 구동되고있는 것을 나타내는 1 차 공정에 의해 구동되는 것을 나타낸다.

개인 DTX 또는 EVR 미셀과 미셀이 성공적으로 PEG 4000 하나에서 공식화 -PLA b를 PEG-에서 DTX와 EVR DDM - B -PLA 2200 또는 PEG 2000 - B -PLA 1800 (그림 1). DTX, EVR하고, DDM은 PEG 4000 유사한 안정성을 보여 주었다 - 48 시간 이상 -PLA 1800 B (그림 2) - -PLA 2200 또는 PEG 2000 나. ...

Watch this Scientific Journal Video about Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles at JoVE.com

Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.

준비 및 개인의 특성과 다중 약물은 물리적으로 고분자 미셀을 포획로드

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar ...

preparation-characterization-individual-multi-drug-loaded-physically

Universidad San Sebastian

Research

JoVE Journal

Chemistry

11.2K 조회수.  Pacific University. The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.

비디오: Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles

Nanomedicine is an emerging form of therapy that harnesses the unique properties of particles that are nanometers in scale for biomedical application. Improving drug delivery to maximize therapeutic outcomes and to reduce drug-associated side effects are some of the cornerstones of present-day nanomedicine. Nanoparticles in particular have found a wide application in cancer treatment. Nanoparticles that offer a high degree of flexibility in design, application, and production based on the tumor microenvironment are projected to be more effective with rapid translation into clinical practice. The polymeric micellar nano-carrier is a popular choice for drug delivery applications.
In this article, we describe a simple and effective protocol for synthesizing drug-loaded, disulfide cross-linked micelles based on the self-assembly of a well-defined amphiphilic linear-dendritic copolymer (telodendrimer, TD). TD is composed of polyethylene glycol (PEG) as the hydrophilic segment and a thiolated cholic acid cluster as the core-forming hydrophobic moiety attached stepwise to an amine-terminated PEG using solution-based peptide chemistry. Chemotherapy drugs, such as paclitaxel (PTX), can be loaded using a standard solvent evaporation method. The O2-mediated oxidation was previously utilized to form intra-micellar disulfide cross-links from free thiol groups on the TDs. However, the reaction was slow and not feasible for large-scale production. Recently, an H2O2-mediated oxidation method was explored as a more feasible and efficient approach, and it was 96 times faster than the previously reported method. Using this approach, 50 g of PTX-loaded, disulfide cross-linked nanoparticles have been successfully produced with narrow particle size distribution and high drug loading efficiency. The stability of the resulting micelle solution is analyzed using disrupting conditions such as co-incubation with a detergent, sodium dodecyl sulfate, with or without a reducing agent. The drug-loaded, disulfide cross-linked micelles demonstrated less hemolytic activity when compared to their non-cross-linked counterparts.

To deliver cancer drugs to tumor sites with high specificity and reduced side effects, new methods based on nanoparticles are required. Here, we describe disulfide cross-linked micelles that can be easily prepared by hydrogen peroxide-mediated oxidation and are able to dissociate efficiently under a reducing tumor environment to release payloads.

가역 디설파이드 가교 미셀 제조를위한 손쉬운 효율적인 접근법

Nanomedicine is an emerging form of therapy that harnesses the unique properties of particles that are nanometers in scale for biomedical application. ...

연구

생화학

Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale (nanoparticles). Nanoparticles can be engineered in a precise fashion where their size, composition and surface chemistry can be carefully controlled. This enables unprecedented freedom to modify some of the fundamental properties of their cargo, such as solubility, diffusivity, biodistribution, release characteristics and immunogenicity. Since their inception, nanoparticles have been utilized in many areas of science and medicine, including drug delivery, imaging, and cell biology1-4. However, it has not been fully utilized outside of "nanotechnology laboratories" due to perceived technical barrier. In this article, we describe a simple method to synthesize a polymer based nanoparticle platform that has a wide range of potential applications. 
The first step is to synthesize a diblock co-polymer that has both a hydrophobic domain and hydrophilic domain. Using PLGA and PEG as model polymers, we described a conjugation reaction using EDC/NHS chemistry5 (Fig 1). We also discuss the polymer purification process. The synthesized diblock co-polymer can self-assemble into nanoparticles in the nanoprecipitation process through hydrophobic-hydrophilic interactions.
The described polymer nanoparticle is very versatile. The hydrophobic core of the nanoparticle can be utilized to carry poorly soluble drugs for drug delivery experiments6. Furthermore, the nanoparticles can overcome the problem of toxic solvents for poorly soluble molecular biology reagents, such as wortmannin, which requires a solvent like DMSO. However, DMSO can be toxic to cells and interfere with the experiment. These poorly soluble drugs and reagents can be effectively delivered using polymer nanoparticles with minimal toxicity. Polymer nanoparticles can also be loaded with fluorescent dye and utilized for intracellular trafficking studies. Lastly, these polymer nanoparticles can be conjugated to targeting ligands through surface PEG. Such targeted nanoparticles can be utilized to label specific epitopes on or in cells7-10.

This article describes a nanoprecipitation method to synthesize polymer-based nanoparticles using diblock co-polymers. We will discuss the synthesis of diblock co-polymers, the nanoprecipitation technique, and potential applications.

Nanoprecipitation 기법을 통해 디블록 고분자 Nanoparticles의 제형

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale ...

생체공학

Preparation and Characterization of SDF-1&#945;-Chitosan-Dextran Sulfate Nanoparticles

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under appropriate conditions. The glycan nanoparticles are useful carriers for protein factors, which facilitate the in vivo delivery of the proteins and sustain their retention in the targeted tissue. The glycan polyelectrolyte complexes are also ideal for protein delivery, as the incorporation is carried out in aqueous solution, which reduces the likelihood of inactivation of the proteins. Proteins with a heparin-binding site adhere to dextran sulfate readily, and are, in turn, stabilized by the binding. These particles are also less inflammatory and toxic when delivered in vivo. In the protocol described below, SDF-1&#945; (Stromal cell-derived factor-1&#945;), a stem cell homing factor, is first mixed and incubated with dextran sulfate. Chitosan is added to the mixture to form polyelectrolyte complexes, followed by zinc sulfate to stabilize the complexes with zinc bridges. The resultant SDF-1&#945;-DS-CS particles are measured for size (diameter) and surface charge (zeta potential). The amount of the incorporated SDF-1&#945; is determined, followed by measurements of its in vitro release rate and its chemotactic activity in a particle-bound form.

The objective of this protocol is to incorporate SDF-1&#945;, a stem cell homing factor, into dextran sulfate-chitosan nanoparticles. The resultant particles are measured for their size and zeta potential, as well as the content, activity, and in vitro release rate of SDF-1&#945; from the nanoparticles.

SDF-1α-키토산 덱스 트란 황산 나노 입자의 제조 및 특성

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under ...

화학

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

탄소 나노 튜브에 의해 안정화 내부 자기 조립 된 지질 입자의 용이 한 제조

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE). Characterization of the copolymer revealed a narrow molecular distribution (PDI &#60; 1.03) and confirmed the degree of polymerization of mPEG122-b-(PheGE)15. The critical micelle concentration of the copolymer was evaluated using an established fluorescence method with the aggregation behavior evaluated by dynamic light scattering and transmission electronic microscopy. The potential of the copolymer for use in drug delivery applications was evaluated in a preliminary manner including in vitro biocompatibility, loading and release of the hydrophobic anti-cancer drug doxorubicin (DOX). A stable micelle formulation of DOX was prepared with drug loading levels up to 14% (wt%), drug loading efficiencies &#62; 60% (w/w) and sustained release of drug over 4 days under physiologically relevant conditions (acidic and neutral pH, presence of albumin). The high drug loading level and sustained release is attributed to stabilizing &#960;-&#960; interactions between DOX and the core-forming block of the micelles.

The key steps of living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE) are described. The resulting block copolymer micelles (BCMs) were loaded with doxorubicin 14% (wt%) and sustained release of drug over 4 days under physiologically relevant conditions was obtained.

π-π 스태킹 상호 작용에 의해 안정화 된 블록 공중 합체 미셀 준비하는 양친 매성 공중 합체의 음이온 중합

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl ...

Intra-lymph Node Injection of Biodegradable Polymer Particles

Generation of adaptive immune response relies on efficient drainage or trafficking of antigen to lymph nodes for processing and presentation of these foreign molecules to T and B lymphocytes. Lymph nodes have thus become critical targets for new vaccines and immunotherapies. A recent strategy for targeting these tissues is direct lymph node injection of soluble vaccine components, and clinical trials involving this technique have been promising. Several biomaterial strategies have also been investigated to improve lymph node targeting, for example, tuning particle size for optimal drainage of biomaterial vaccine particles. In this paper we present a new method that combines direct lymph node injection with biodegradable polymer particles that can be laden with antigen, adjuvant, or other vaccine components. In this method polymeric microparticles or nanoparticles are synthesized by a modified double emulsion protocol incorporating lipid stabilizers. Particle properties (e.g.&#160;size, cargo loading) are confirmed by laser diffraction and fluorescent microscopy, respectively. Mouse lymph nodes are then identified by peripheral injection of a nontoxic tracer dye that allows visualization of the target injection site and subsequent deposition of polymer particles in lymph nodes. This technique allows direct control over the doses and combinations of biomaterials and vaccine components delivered to lymph nodes and could be harnessed in the development of new biomaterial-based vaccines.

Lymph nodes are the immunological tissues that orchestrate immune response and are a critical target for vaccines. Biomaterials have been employed to better target lymph nodes and to control delivery of antigens or adjuvants. This paper describes a technique combining these ideas to inject biocompatible polymer particles into lymph nodes.

생분해성 폴리머 입자의 림프절 내 주입

Generation of adaptive immune response relies on efficient drainage or trafficking of antigen to lymph nodes for processing and presentation of these ...

Assembly and Characterization of Polyelectrolyte Complex Micelles

Polyelectrolyte complex micelles (PCMs), core-shell nanoparticles formed by self-assembly of charged polymers in aqueous solution, provide a powerful platform for exploring the physics of polyelectrolyte interactions and also offer a promising solution to the pressing problem of delivering therapeutic oligonucleotides in vivo. Developing predictive structure-property relationships for PCMs has proven difficult, in part due to the presence of strong kinetic traps during nanoparticle self-assembly. This article discusses criteria for choosing polymers for PCM construction and provides protocols based on salt annealing that enable assembly of repeatable, low-polydispersity nanoparticles. We also discuss PCM characterization using light scattering, small-angle X-ray scattering, and electron microscopy.

We provide protocols and representative data for designing, assembling, and characterizing polyelectrolyte complex micelles, core-shell nanoparticles formed by polyelectrolytes and hydrophilic charged-uncharged block copolymers.

Polyelectrolyte complex micelles (PCMs), core-shell nanoparticles formed by self-assembly of charged polymers in aqueous solution, provide a powerful ...

Preparation and Characterization of Lipophilic Doxorubicin Pro-drug Micelles

Micelles have been successfully used for the delivery of anticancer drugs. Amphiphilic polymers form core-shell structured micelles in an aqueous environment through self-assembly. The hydrophobic core of micelles functions as a drug reservoir and encapsulates hydrophobic drugs. The hydrophilic shell prevents the aggregation of micelles and also prolongs their systemic circulation in vivo. In this protocol, we describe a method to synthesize a doxorubicin lipophilic pro-drug, doxorubicin-palmitic acid (DOX-PA), which will enhance drug loading into micelles. A pH-sensitive hydrazone linker was used to conjugate doxorubicin with the lipid, which facilitates the release of free doxorubicin inside cancer cells. Synthesized DOX-PA was purified with a silica gel column using dichloromethane/methanol as the eluent. Purified DOX-PA was analyzed with thin layer chromatography (TLC) and 1H-Nuclear Magnetic Resonance Spectroscopy (1H-NMR). A film dispersion method was used to prepare DOX-PA loaded DSPE-PEG micelles. In addition, several methods for characterizing micelle formulations are described, including determination of DOX-PA concentration and encapsulation efficiency, measurement of particle size and distribution, and assessment of in vitro anticancer activities. This protocol provides useful information regarding the preparation and characterization of drug-loaded micelles and thus will facilitate the research and development of novel micelle-based cancer nanomedicines.

A protocol for the preparation and characterization of lipophilic doxorubicin pro-drug loaded 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG) micelles is described.

친 유성 독소루비신 전구 약물 미셀의 제조 및 특성화

Micelles have been successfully used for the delivery of anticancer drugs. Amphiphilic polymers form core-shell structured micelles in an aqueous ...

Phase Change Dimethyldioctadecylammonium-Shelled Microdroplets as a Promising Drug Delivery System: Results on 3D Spheroids of Mammalian Tumor Cells

Significant improvement of phase-change perfluorocarbon microdroplets (MDs) in the vast theranostic scenario passes through the optimization of the MDs composition with respect to synthesis efficiency, stability, and drug delivery capability. To this aim, decafluoropentane (DFP) MDs stabilized by a shell of dimethyldioctadecylammonium bromide (DDAB) cationic surfactant were designed. A high concentration of DDAB-MDs was readily obtained within a few seconds by pulsed high-power insonation, resulting in low polydisperse 1 &#181;m size droplets. Highly positive &#950;-potential, together with a long, saturated hydrocarbon chains of the DDAB shell, are key factors to stabilize the droplet and the drug cargo therein. The high affinity of the DDAB shell with cell plasma membrane allows for localized chemotherapeutics delivery by increasing the drug concentration at the tumor cell interface and boosting the uptake. This would turn DDAB-MDs into a relevant drug delivery tool exhibiting high antitumor activity at very low drug doses.
In this work, the efficacy of such an approach is shown to dramatically improve the effect of doxorubicin against 3D spheroids of mammalian tumor cells, MDA-MB-231. The use of&#160;three-dimensional (3D) cell cultures developed in the form of multicellular tumor spheroids (i.e., densely packed cells in a spherical shape) has numerous advantages compared to 2D cell cultures: in addition to have the potential to bridge the gap between conventional in vitro studies and animal testing, it will improve the ability to perform more predictive in vitro screening assays for preclinical drug development or evaluate the potential of off-label drugs and new co-targeting strategies.

Decafluoropentane microdroplets developed with a shell of dimethyldioctadecylammonium bromide exhibited an exceptional colloidal stability and an actractive biointerface. DDAB-MDs proved to be efficient drug reservoirs characterized by a high affinity to plasma membranes together with enhanced uptake and antitumor activity of Doxorubicin against human triple-negative breast cancer (MDA-MB-231) 3D model.

Significant improvement of phase-change perfluorocarbon microdroplets (MDs) in the vast theranostic scenario passes through the optimization of the MDs ...

Preparation and Characterization of Nanoliposomes for the Entrapment of Bioactive Hydrophilic Globular Proteins

Liposome nanocapsules have been applied for many purposes in the pharmaceutical, cosmetic, and food industries. Attributes of liposomes include their biocompatibility, biodegradability, non-immunogenicity, non-toxicity, and ability to entrap both hydrophilic and hydrophobic compounds. The classical hydration of thin lipid films in an organic solvent is applied herein as a technique to encapsulate tarin, a plant lectin, in nanoliposomes. Nanoliposome size, stability, entrapment efficiency, and morphological characterization are described in detail. The nanoliposomes are prepared using 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (ammonium salt; DSPE-MPEG 2000), and cholesterylhemisuccinate (CHEMS) as the main constituents. Lipids are first dissolved in chloroform to obtain a thin lipid film that is subsequently rehydrated in ammonium sulfate solution containing the protein to be entrapped and incubated overnight. Then, sonication and extrusion techniques are applied to generate nanosized unilamellar vesicles. The size and polydispersity index of the nanovesicles are determined by dynamic light scattering, while nanovesicle morphology is assessed by scanning electron microscopy. Entrapment efficiency is determined by the ratio of the amount of unencapsulated protein to original amount of initially loaded protein. Homogeneous liposomes are obtained with an average size of 155 nm and polydispersity index value of 0.168. A high entrapment efficiency of 83% is achieved.

This study describes classical hydration using the thin lipid film method for nanoliposome preparation followed by nanoparticle characterization. A 47 kDa-hydrophilic and globular protein, tarin, is successfully encapsulated as a strategy to improve stability, avoid fast clearance, and promote controlled release. The method can be adapted to hydrophobic molecules encapsulation.

생리 활성 친수성 구형 단백질의 함정에 대한 나노 리포좀의 준비 및 특성화

Liposome nanocapsules have been applied for many purposes in the pharmaceutical, cosmetic, and food industries. Attributes of liposomes include their ...