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 border="0" cellpadding="0" cellspacing="0">
	<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&#160;</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&#181;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><a href="http://www.graphpad.com/">www.graphpad.com</a></td>
			<td></td>
			<td>Analysis software</td>
		</tr>
		<tr>
			<td>Zorbax SB-C8 Rapid Resolution cartridge&#160;</td>
			<td>Agilent Technologies</td>
			<td>866953-906</td>
			<td>4.6 &#215;75mm, 3.5 micron</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

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

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid phase by using combinatorial chemistry. One of the most well studied classes of peptidomimetics is peptoids. Peptoids are easy to synthesize and have been shown to be proteolysis-resistant and cell-permeable. Over the past decade, many useful protein ligands have been identified through screening of peptoid libraries. However, most of the ligands identified from peptoid libraries do not display high affinity, with rare exceptions. This may be due, in part, to the lack of chiral centers and conformational constraints in peptoid molecules. Recently, we described a new synthetic route to access peptide tertiary amides (PTAs). PTAs are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. With side chains on both &#945;-carbon and main chain nitrogen atoms, the conformation of these molecules are greatly constrained by sterical hindrance and allylic 1,3 strain. (Figure 1) Our study suggests that these PTA molecules are highly structured in solution and can be used to identify protein ligands. We believe that these molecules can be a future source of high-affinity protein ligands. Here we describe the synthetic method combining the power of both split-and-pool and sub-monomer strategies to synthesize a sample one-bead one-compound (OBOC) library of PTAs.

Peptide tertiary amides (PTAs) are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. Here we describe a synthetic method which combines&#160;both split-and-pool and sub-monomer strategies to synthesize a one-bead one-compound library of PTAs.

분할 및 풀 합성 펩타이드 급 아미드 도서관의 특성

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid ...

연구

화학

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

기능화의 합성 및 특성 금속 - 유기 프레임 워크

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

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.

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

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 ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

합성, 특성 및 하이브리드 금 / CD 및 금 /은 ZnS 코어 / 쉘 나노 입자의 작용 화

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

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.

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

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 ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

단일 분자 수준에서 순환 고분자의 합성 및 용융 상태에서 그들의 확산 운동의 특성

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing

Effective hair dyeing through in situ incubation of keratin hair with the products of fungal laccase-catalyzed polymerization of plant phenols has been previously demonstrated. However, the dyeing process takes a long time to complete compared to commercial hair-dyeing products. To overcome this bottleneck, pre-synthesized polymeric products of the oxidative reaction of Trametes versicolor laccase on catechin and catechol, either with or without mordant agents (e.g., FeSO4), were here employed to achieve permanent keratin hair dyeing in various colors and shades. The laccase action in acidic sodium acetate buffer led to a deep black coloration after coupling reactions between the plant phenols. The colored dye products were then desalted and concentrated with ultrafiltration. The dyes, with or without mordant agents, caused a significant increase in &#916;E values (i.e., color difference value) in gray human hair within 2.5 hours. In addition, different keratin colors and shades were induced depending upon the mordanting and pH changes. The dyed hair also exhibited a strong resistance to detergent treatments, indicating that our methods can give rise to permanent hair dyeing.&#160;Overall, our work has provided novel insight into developing eco-friendly hair-dyeing methods as alternatives to commercial toxic diamine-based dyes.

Here, we present a protocol to use pre-synthesized polymeric products derived from fungal laccase-catalyzed polymerization of plant phenols, either with or without mordant agents (e.g., FeSO4), to induce detergent-resistant keratin hair dyeing within 2.5 hours.

직접 또는 모던 기반 머리 염색에 대한 공장 페놀 유래 고분자 염료의 합성

Effective hair dyeing through in situ incubation of keratin hair with the products of fungal laccase-catalyzed polymerization of plant phenols has been ...

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

Paramagnetic complexes of gadolinium(III) with acyclic or macrocyclic chelates are the most commonly used contrast agents (CAs) for magnetic resonance imaging (MRI). Their purpose is to enhance the relaxation rate of water protons in tissue, thus increasing the MR image contrast and the specificity of the MRI measurements. Current clinically approved contrast agents are low molecular weight molecules that are rapidly cleared from the body. The use of dendrimers as carriers of paramagnetic chelators can play an important role in the future development of more efficient MRI contrast agents. Specifically, the increase in local concentration of the paramagnetic species results in a higher signal contrast. Furthermore, this CA provides a longer tissue retention time due to its high molecular weight and size. Here, we demonstrate a convenient procedure for the preparation of macromolecular MRI contrast agents based on poly(amidoamine) (PAMAM) dendrimers with monomacrocyclic DOTA-type chelators (DOTA &#8211; 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate). The chelating unit was appended by exploiting the reactivity of the isothiocyanate (NCS) group towards the amine surface groups of the PAMAM dendrimer to form thiourea bridges. Dendrimeric products were purified and analyzed by means of nuclear magnetic resonance spectroscopy, mass spectrometry, and elemental analysis. Finally, high resolution MR images were recorded and the signal contrasts obtained from the prepared dendrimeric and the commercially available monomeric agents were compared.

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

This protocol describes the preparation and characterization of a dendrimeric magnetic resonance imaging (MRI) contrast agent that carries cyclen-based macrocyclic chelates coordinating paramagnetic gadolinium ions. In a series of MRI experiments in vitro, this agent produced an amplified MRI signal when compared to the commercially available monomeric analogue.

준비 및<em&gt; 체외</em&gt; 자기 공명 영상에 대한 덴드리머 기반 대조 대리인의 특성

Paramagnetic complexes of gadolinium(III) with acyclic or macrocyclic chelates are the most commonly used contrast agents (CAs) for magnetic resonance ...

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

Physical thermal deposition in a high vacuum environment is a clean and controllable method for fabricating novel molecular nanostructures on graphene. We present methods for depositing and passively manipulating C60 molecules on rippled graphene that advance the pursuit of realizing applications involving 1D C60/graphene hybrid structures. The techniques applied in this exposition are geared towards high vacuum systems with preparation areas capable of supporting molecular deposition as well as thermal annealing of the samples. We focus on C60 deposition at low pressure using a homemade Knudsen cell connected to a scanning tunneling microscopy (STM) system. The number of molecules deposited is regulated by controlling the temperature of the Knudsen cell and the deposition time. One-dimensional (1D) C60 chain structures with widths of two to three molecules can be prepared via tuning of the experimental conditions. The surface mobility of the C60 molecules increases with annealing temperature allowing them to move within the periodic potential of the rippled graphene. Using this mechanism, it is possible to control the transition of 1D C60 chain structures to a hexagonal close packed quasi-1D stripe structure.

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

Here we present a protocol for the fabrication of C60/graphene hybrid nanostructures by physical thermal evaporation. Particularly, the proper manipulation of deposition and annealing conditions allow the control over the creation of 1D and quasi 1D C60 structures on rippled graphene.

준비 및 C60/Graphene 하이브리드 Nanostructures의 특성화

Physical thermal deposition in a high vacuum environment is a clean and controllable method for fabricating novel molecular nanostructures on graphene. We ...