scholarly journals Tuneable Peptide Cross-Linked Nanogels for Enzyme Triggered Protein Delivery

2020 ◽  
Author(s):  
Lucia Massi ◽  
Adrian Najer ◽  
Robert Chapman ◽  
Christopher Spicer ◽  
Valeria Nele ◽  
...  
Keyword(s):  
Self Assembly ◽  
Protein Delivery ◽  
Elevated Temperatures ◽  
Inflammatory Diseases ◽  
Polymeric Nanoparticles ◽  
Drug Carrier ◽  
Specific Protein ◽  
Correlation Spectroscopy ◽  
Solution Temperature ◽  
Temperature Sensitive

<p>Many diseases are associated with the dysregulated activity of enzymes, such as matrix metalloproteinases (MMPs). This dysregulation can be leveraged in drug delivery to achieve disease- or site-specific cargo release. Self-assembled polymeric nanoparticles are versatile drug carrier materials due to the accessible diversity of polymer chemistry. However, efficient loading of sensitive cargo, such as proteins, and introducing functional enzyme-responsive behaviour remain challenging. Herein, peptide-crosslinked, temperature-sensitive nanogels for protein delivery were designed to respond to MMP-7, which is overexpressed in many pathologies including cancer and inflammatory diseases. The incorporation of <i>N-</i>cyclopropylacrylamide (NCPAM) into <i>N</i>-isopropylacrylamide (NIPAM)-based copolymers enabled us to tune the polymer lower critical solution temperature from 33 to 44 °C, allowing the encapsulation of protein cargo and nanogel-crosslinking at slightly elevated temperatures. This approach resulted in nanogels that were held together by MMP-sensitive peptides for enzyme-specific protein delivery. We employed a combination of cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), small angle neutron scattering (SANS), and fluorescence correlation spectroscopy (FCS) to precisely decipher the morphology, self-assembly mechanism, enzyme-responsiveness, and model protein loading/release properties of our nanogel platform. Simple variation of the peptide linker sequence and combining multiple different crosslinkers will enable us to adjust our platform to target specific diseases in the future.</p>

scholarly journals Tuneable Peptide Cross-Linked Nanogels for Enzyme Triggered Protein Delivery

2020 ◽  
Author(s):  
Lucia Massi ◽  
Adrian Najer ◽  
Robert Chapman ◽  
Christopher Spicer ◽  
Valeria Nele ◽  
...  
Keyword(s):  
Self Assembly ◽  
Protein Delivery ◽  
Elevated Temperatures ◽  
Inflammatory Diseases ◽  
Polymeric Nanoparticles ◽  
Drug Carrier ◽  
Specific Protein ◽  
Correlation Spectroscopy ◽  
Solution Temperature ◽  
Temperature Sensitive

<p>Many diseases are associated with the dysregulated activity of enzymes, such as matrix metalloproteinases (MMPs). This dysregulation can be leveraged in drug delivery to achieve disease- or site-specific cargo release. Self-assembled polymeric nanoparticles are versatile drug carrier materials due to the accessible diversity of polymer chemistry. However, efficient loading of sensitive cargo, such as proteins, and introducing functional enzyme-responsive behaviour remain challenging. Herein, peptide-crosslinked, temperature-sensitive nanogels for protein delivery were designed to respond to MMP-7, which is overexpressed in many pathologies including cancer and inflammatory diseases. The incorporation of <i>N-</i>cyclopropylacrylamide (NCPAM) into <i>N</i>-isopropylacrylamide (NIPAM)-based copolymers enabled us to tune the polymer lower critical solution temperature from 33 to 44 °C, allowing the encapsulation of protein cargo and nanogel-crosslinking at slightly elevated temperatures. This approach resulted in nanogels that were held together by MMP-sensitive peptides for enzyme-specific protein delivery. We employed a combination of cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), small angle neutron scattering (SANS), and fluorescence correlation spectroscopy (FCS) to precisely decipher the morphology, self-assembly mechanism, enzyme-responsiveness, and model protein loading/release properties of our nanogel platform. Simple variation of the peptide linker sequence and combining multiple different crosslinkers will enable us to adjust our platform to target specific diseases in the future.</p>

scholarly journals Effect of Phenolic Acids on Temperature-sensitive Property of Self-assembly of Ionic Pair of Poly(ethylene imine)/(phenylthio)Acetic Acid

2021 ◽  
Author(s):  
Fanyu Zhao ◽  
Jin-Chul Kim
Keyword(s):  
Acetic Acid ◽  
Phenolic Acids ◽  
Self Assembly ◽  
Room Temperature ◽  
Time Lapse ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Ionic Pair ◽  
Ethylene Imine ◽  
Interfacial Activity

Abstract The ionic pair self-assembly (IPSAM) composed of poly(ethyleneimine) (PEI) and (phenylthio)acetic acid (PTA) was prepared and the effect of phenolic acids (PAs) (e.g. cinnamic acid (CA), hydroxycinnamic acid (HCA), and dihydroxycinnamic acid (DHCA)) on the upper critical solution temperature (UCST) and the temperature-responsive releasing property of IPSAM were investigated. PEI/PTA ionic pair showed a UCST behavior and the PAs decreased the UCST effective in the order of DHCA > HCA > CA. The PAs were thought to attach to the PEI chain of PEI/PTA ionic pair as pendants. According to the interfacial tensiometry, PEI/PTA(3/7) ionic pair was found to be air/water interface-active due to their amphiphilic property. CA had little effect on the interfacial activity of the ionic pair. HCA and HDCA significantly decreased the interfacial activity possibly because they are more polar than CA thus the hydrophilic and lipophilic balance of PEI/PTA ionic pair could be broken by their attachment to PEI chains. IPSAM was found as nanoparticles whose diameter was tens of nanometer and PAs had little effect on the shape and the size of IPSAM, once the UCST of PEI/PTA/PA ionic pair was above room temperature where the TEM micrographs were taken. If the UCST of PEI/PTA/PA ionic pair was below room temperature, no particulate matters were found on the TEM micrographs. The release degree of cargo loaded in IPSAM increased slowly with time lapse below UCST. Whereas, the release degree increased rapidly with time lapse above UCST, possibly because of the thermally-induced disintegration of IPSAM.

scholarly journals Dendrimer-like supramolecular assembly of proteins with a tunable size and valency through stepwise iterative growth

2021 ◽  
Author(s):  
Jin Ho Bae ◽  
Hong-Sik Kim ◽  
Gijeong Kim ◽  
Ji-Joon Song ◽  
Hak-Sung Kim
Keyword(s):  
Self Assembly ◽  
Building Block ◽  
Protein Delivery ◽  
Supramolecular Assembly ◽  
Protein Assembly ◽  
Specific Protein ◽  
Single Step ◽  
Practical Applications ◽  
Order Of Magnitude ◽  
The Creation

The assembly of proteins in a programmable manner provides insight into the underlying mechanisms of protein self-assembly in nature as well as the creation of novel functional nanomaterials for practical applications. Despite many advances, however, a rational protein assembly with an easy scalability in terms of size and valency remains a challenging task. Here, we present a simple bottom-up approach to the supramolecular protein assembly with a tunable size and valency in a programmable manner. The dendrimer-like protein assembly, called a prodrimer, was constructed using a total of three monomeric proteins: a core and two building-block proteins. The prodrimer generations were grown by a stepwise and alternate addition of a building block using two pairs of orthogonal protein-peptide interactions, leading to a higher-generation prodrimer with a mega-dalton size and multi-valency. The valency of the prodrimers at the periphery was tunable with the generation, enabling a single-step functionalization. A second-generation prodrimer functionalized with a target-specific protein binder showed a three-order of magnitude increase in binding affinity compared to a monomeric counterpart due to the avidity. The prodrimers functionalized with a targeting moiety and a cytotoxic protein cargo exhibited a highly enhanced cellular cytotoxicity, exemplifying their utility as a protein delivery platform. The present approach can be effectively used in the creation of protein architectures with new functions for biotechnological and medical applications.

Freezing Assisted Protein Delivery by Using Polymeric Cryoprotectant

2014 ◽  
Vol 1622 ◽  
pp. 123-127
Author(s):  
Sana AHMED ◽  
Kazuaki MATSUMURA
Keyword(s):  
Cell Membrane ◽  
Protein Delivery ◽  
Polymeric Micelles ◽  
Polymeric Nanoparticles ◽  
Drug Carrier ◽  
Intracellular Delivery ◽  
Drug Carriers ◽  
Freeze Concentration ◽  
Enhanced Absorption ◽  
Novel Drug

ABSTRACTA number of drug carrier systems such as liposomes, polymeric-nanoparticles, microparticles, polymeric micelles have been investigated for intracellular delivery. Among these liposomes are the potential drug vehicles for efficient cytosolic delivery. They have an adhesive property for cell membrane to encapsulate the drug or protein effectively and showing the enhanced absorption rate. One of the problems could be the difficulty of incorporation of the drug or protein into cell. Therefore many studies of the drug carriers have been developed to enhance the intracellular delivery of materials. Here we propose the novel method to improve the intracellular uptaking by using freeze concentration. Solutes are excluded from ice crystallization and concentrated in the remaining solution during freezing by freezing concentration. We have reported that polymeric cryoprotectant which is carboxylated poly-L-lysine was adsorbed on to the cell membrane during freezing and caused effective freeze concentration. In this study we investigated that delivery of protein effectively taking place by liposome as a carrier agent. It was successfully delivered protein to L929 cells via freeze concentration using polymeric cryoprotectant as a novel drug delivery.

Thermosensitive Nanocontainers Prepared from Poly(N-isopropylacrylamide-co-N-(hydroxylmethyl)acrylamide)-g-Poly(lactide)

2006 ◽  
Vol 6 (9) ◽  
pp. 2896-2901 ◽  
Author(s):  
Yan Zhang ◽  
Wuli Yang ◽  
Changchun Wang ◽  
Wei Wu ◽  
Shoukuan Fu
Keyword(s):  
Self Assembly ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Critical Solution Temperature ◽  
Spherical Structure ◽  
Thermally Responsive ◽  
Transmission Electron ◽  
Isopropyl Acrylamide ◽  
Fundamental Research ◽  
Spatial Specificity

Thermally-responsive graft copolymer of poly(N-isopropylacrylamide-co-N-(hydroxylmethyl)acrylamide)-g-poly(lactide) was synthesized by ring-opening polymerization of D,L-lactide (LA). The polymerization was initiated by the hydroxy group of poly(N-isopropyl acrylamide-co-N-(hydroxylmethyl)acrylamide), using stannous octoate as catalyst. The resulting polymer was temperature-sensitive and the lower critical solution temperature (LCST) was affected by their composition. The chemical structure and physical properties of the grafted copolymers were investigated by various methods. Nanocontainers formed from the self-assembly of poly(N-isopropylacrylamide-co-N-(hydroxylmethyl) acrylamide)-g-poly(lactide) were characterized by transmission electron microscopy (TEM), and a spherical structure was observed. Dynamic light scattering (DLS) results indicate that the particle size increased with the increase of polylactide content in the copolymer. The properties of this polymer are interesting for both industrial application and fundamental research. In particular it will combine a spatial specificity in a passive manner and a temperature-responsive active targeting mechanism for drug delivery system.

scholarly journals Synthesis and self-assembly of curcumin-modified amphiphilic polymeric micelles with antibacterial activity

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Caio H. N. Barros ◽  
Dishon W. Hiebner ◽  
Stephanie Fulaz ◽  
Stefania Vitale ◽  
Laura Quinn ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Self Assembly ◽  
Glycolic Acid ◽  
Extracellular Polymeric Substances ◽  
Polymeric Micelles ◽  
Polymeric Nanoparticles ◽  
Enhanced Resistance ◽  
Antimicrobial Nanoparticles ◽  
Good Penetration ◽  
Antibiofilm Agents

Abstract Background The ubiquitous nature of bacterial biofilms combined with the enhanced resistance towards antimicrobials has led to the development of an increasing number of strategies for biofilm eradication. Such strategies must take into account the existence of extracellular polymeric substances, which obstruct the diffusion of antibiofilm agents and assists in the maintenance of a well-defended microbial community. Within this context, nanoparticles have been studied for their drug delivery efficacy and easily customised surface. Nevertheless, there usually is a requirement for nanocarriers to be used in association with an antimicrobial agent; the intrinsically antimicrobial nanoparticles are most often made of metals or metal oxides, which is not ideal from ecological and biomedical perspectives. Based on this, the use of polymeric micelles as nanocarriers is appealing as they can be easily prepared using biodegradable organic materials. Results In the present work, micelles comprised of poly(lactic-co-glycolic acid) and dextran are prepared and then functionalised with curcumin. The effect of the functionalisation in the micelle’s physical properties was elucidated, and the antibacterial and antibiofilm activities were assessed for the prepared polymeric nanoparticles against Pseudomonas spp. cells and biofilms. It was found that the nanoparticles have good penetration into the biofilms, which resulted in enhanced antibacterial activity of the conjugated micelles when compared to free curcumin. Furthermore, the curcumin-functionalised micelles were efficient at disrupting mature biofilms and demonstrated antibacterial activity towards biofilm-embedded cells. Conclusion Curcumin-functionalised poly(lactic-co-glycolic acid)-dextran micelles are novel nanostructures with an intrinsic antibacterial activity tested against two Pseudomonas spp. strains that have the potential to be further exploited to deliver a secondary bioactive molecule within its core. Graphic Abstract

scholarly journals Kinked Bisamides as Efficient Supramolecular Foam Cell Nucleating Agents for Low-Density Polystyrene Foams with Homogeneous Microcellular Morphology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1094
Author(s):  
Bastian Klose ◽  
Daniel Kremer ◽  
Merve Aksit ◽  
Kasper P. van der Zwan ◽  
Klaus Kreger ◽  
...  
Keyword(s):  
Cell Size ◽  
Self Assembly ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Foam Cell ◽  
Cell Structure ◽  
Expansion Ratio ◽  
Low Density ◽  
Nucleating Agents ◽  
Foam Density

Polystyrene foams have become more and more important owing to their lightweight potential and their insulation properties. Progress in this field is expected to be realized by foams featuring a microcellular morphology. However, large-scale processing of low-density foams with a closed-cell structure and volume expansion ratio of larger than 10, exhibiting a homogenous morphology with a mean cell size of approximately 10 µm, remains challenging. Here, we report on a series of 4,4′-diphenylmethane substituted bisamides, which we refer to as kinked bisamides, acting as efficient supramolecular foam cell nucleating agents for polystyrene. Self-assembly experiments from solution showed that these bisamides form supramolecular fibrillary or ribbon-like nanoobjects. These kinked bisamides can be dissolved at elevated temperatures in a large concentration range, forming dispersed nano-objects upon cooling. Batch foaming experiments using 1.0 wt.% of a selected kinked bisamide revealed that the mean cell size can be as low as 3.5 µm. To demonstrate the applicability of kinked bisamides in a high-throughput continuous foam process, we performed foam extrusion. Using 0.5 wt.% of a kinked bisamide yielded polymer foams with a foam density of 71 kg/m3 and a homogeneous microcellular morphology with cell sizes of ≈10 µm, which is two orders of magnitude lower compared to the neat polystyrene reference foam with a comparable foam density.

scholarly journals Mutations in the Bacillus subtilis β Clamp That Separate Its Roles in DNA Replication from Mismatch Repair

2010 ◽  
Vol 192 (13) ◽  
pp. 3452-3463 ◽  
Author(s):  
Nicole M. Dupes ◽  
Brian W. Walsh ◽  
Andrew D. Klocko ◽  
Justin S. Lenhart ◽  
Heather L. Peterson ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Dna Replication ◽  
Mismatch Repair ◽  
Mutation Frequency ◽  
Elevated Temperatures ◽  
Temperature Sensitive ◽  
Mutant Form ◽  
Appreciable Effect ◽  
Missense Mutations ◽  
Dna Mismatch

ABSTRACT The β clamp is an essential replication sliding clamp required for processive DNA synthesis. The β clamp is also critical for several additional aspects of DNA metabolism, including DNA mismatch repair (MMR). The dnaN5 allele of Bacillus subtilis encodes a mutant form of β clamp containing the G73R substitution. Cells with the dnaN5 allele are temperature sensitive for growth due to a defect in DNA replication at 49°C, and they show an increase in mutation frequency caused by a partial defect in MMR at permissive temperatures. We selected for intragenic suppressors of dnaN5 that rescued viability at 49°C to determine if the DNA replication defect could be separated from the MMR defect. We isolated three intragenic suppressors of dnaN5 that restored growth at the nonpermissive temperature while maintaining an increase in mutation frequency. All three dnaN alleles encoded the G73R substitution along with one of three novel missense mutations. The missense mutations isolated were S22P, S181G, and E346K. Of these, S181G and E346K are located near the hydrophobic cleft of the β clamp, a common site occupied by proteins that bind the β clamp. Using several methods, we show that the increase in mutation frequency resulting from each dnaN allele is linked to a defect in MMR. Moreover, we found that S181G and E346K allowed growth at elevated temperatures and did not have an appreciable effect on mutation frequency when separated from G73R. Thus, we found that specific residue changes in the B. subtilis β clamp separate the role of the β clamp in DNA replication from its role in MMR.

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