Synthesis and preliminary evaluation of poly(amidoamine)–melittin conjugates as endosomolytic polymers and/or potential anticancer therapeutics

From oncolytic peptides to oncolytic polymers: A new paradigm for oncotherapy

Traditional cancer therapy methods, especially those directed against specific intracellular targets or signaling pathways, are not powerful enough to overcome tumor heterogeneity and therapeutic resistance. Oncolytic peptides that can induce membrane lysis-mediated cancer cell death and subsequent anticancer immune responses, has provided a new paradigm for cancer therapy. However, the clinical application of oncolytic peptides is always limited by some factors such as unsatisfactory bio-distribution, poor stability, and off-target toxicity. To overcome these limitations, oncolytic polymers stand out as prospective therapeutic materials owing to their high stability, chemical versatility, and scalable production capacity, which has the potential to drive a revolution in cancer treatment. This review provides an overview of the mechanism and structure-activity relationship of oncolytic peptides. Then the oncolytic peptides-mediated combination therapy and the nano-delivery strategies for oncolytic peptides are summarized. Emphatically, the current research progress of oncolytic polymers has been highlighted. Lastly, the challenges and prospects in the development of oncolytic polymers are discussed.

Recent developments in animal venom peptide nanotherapeutics with improved selectivity for cancer cells

Animal venoms are a rich source of bioactive peptides that efficiently modulate key receptors and ion channels involved in cellular excitability to rapidly neutralize their prey or predators. As such, they have been a wellspring of highly useful pharmacological tools for decades. Besides targeting ion channels, some venom peptides exhibit strong cytotoxic activity and preferentially affect cancer over healthy cells. This is unlikely to be driven by an evolutionary impetus, and differences in tumor cells and the tumor microenvironment are probably behind the serendipitous selectivity shown by some venom peptides. However, strategies such as bioconjugation and nanotechnologies are showing potential to improve their selectivity and potency, thereby paving the way to efficiently harness new anticancer mechanisms offered by venom peptides. This review aims to highlight advances in nano- and chemotherapeutic tools and prospective anti-cancer drug leads derived from animal venom peptides.

Entropically driven controlled release of paclitaxel from poly(2-ethyl-2-oxazoline) coated maghemite nanostructures for magnetically guided cancer therapy

Theranostic nanostructures serve a dual purpose of therapy and diagnosis. A major fraction of these are based on polymer coated magnetic nanostructures of iron oxides (magnetite and maghemite), owing to the efficient drug loading capacity of polymer shells and enhanced magnetic contrast effects of the iron oxide core. In the current work we are proposing poly(2-ethyl-2-oxazoline) coated linear thermoresponsive nanostructures of maghemite (γ-Fe₂O₃) for potential application in targeted cancer therapy. The polymer coating was obtained via a modified sol-gel technique based on entropically driven phase separation of poly(2-ethyl-2-oxazoline) above its cloud point (CP) temperature of 63 °C in water. The developed nanostructures were further loaded with paclitaxel, a polar anticancer compound at room temperature (25 °C). The entropically driven release of paclitaxel at various concentrations and physiological temperatures was modeled and their application to the PC3 prostrate cancer cell line was investigated by treating in vitro. The steering efficiency of the magnetic nanostructures during their navigation through large blood vessels was also analyzed with the help of a synthetic model of the human axillary artery. The proposed application of these newly developed nanostructures can easily be extended towards localized delivery of additional polar anticancer drugs like cisplatin and doxorubicin.

A Stimuli-Responsive, Binary Reagent System for Rapid Isolation of Protein Biomarkers

Magnetic microbeads exhibit rapid separation characteristics and are widely employed for biomolecule and cell isolations in research laboratories, clinical diagnostics assays, and cell therapy manufacturing. However, micrometer particle diameters compromise biomarker recognition, which leads to long incubation times and significant reagent demands. Here, a stimuli-responsive binary reagent system is presented that combines the nanoscale benefits of efficient biomarker recognition and the microscale benefits of rapid magnetic separation. This system comprises magnetic nanoparticles and polymer-antibody (Ab) conjugates that transition from hydrophilic nanoscale reagents to microscale aggregates in response to temperature stimuli. The binary reagent system was benchmarked against Ab-labeled Dynabeads in terms of biomarker isolation kinetics, assay speed, and reagent needs. Surface plasmon resonance (SPR) measurements showed that polymer conjugation did not significantly alter the Ab's binding affinity or kinetics. ELISA analysis showed that the unconjugated Ab, polymer-Ab conjugates, and Ab-labeled Dynabeads exhibited similar equilibrium dissociation constants (Kd), ∼2 nM. However, the binary reagent system isolated HIV p24 antigen from spiked serum specimens (150 pg/mL) much more quickly than Dynabeads, which resulted in shorter binding times by tens of minutes, or about 30-50% shorter overall assay times. The binary reagent system showed improved performance because the Ab molecules were not conjugated to large, solid microparticle surfaces. This stimuli-responsive binary reagent system illustrates the potential advantages of nanoscale reagents in molecule and cell isolations for both research and clinical applications.

Poly(amidoamine)–BSA conjugates synthesised by Michael addition reaction retained enzymatic activity

A bioconjugate synthesised using a “grafted to” method and Michael addition reaction retained the activity of the native protein.

Cationic poly(amidoamine) promotes cytosolic delivery of bovine RNase A in melanoma cells, while maintaining its cellular toxicity

Ribonucleases are known to cleave ribonucleic acids, inducing cell death. RNase A, a member of the ribonuclease family, generally displayed poor in vitro activity. This has been attributed to factors such as low intracellular delivery. Poly(amidoamine)s have been used to promote the translocation of non-permeant proteins to the cytosol. Our objective was to demonstrate that poly(amidoamine)s could potentially promote the delivery of RNase A to selected cell line. Interactions of three cationic poly(amidoamine)s (P1, P2 and ISA1) with wild-type bovine RNase A were investigated using gel retardation assays, DLS and microcalorimetry. Although the polymers and the protein are essentially cationic at physiological pH, complexation between the PAAs and RNase A was observed. The high sensitivity differential scanning calorimetry (HSDSC) thermograms demonstrated that the thermal stability of the protein was reduced when complexed with ISA1 (T_max decreased by 6.5 °C) but was not affected by P1 and P2. All the polymers displayed low cytotoxicity towards non-cancerous cells (IC₅₀ > 3.5 mg mL^-1). While RNase A alone was not toxic to mouse melanoma cells (B16F1), P1 was able to promote cytosolic delivery of biologically active RNase A, increasing cell death (IC₅₀ = 0.09 mg mL^-1).

Novel chimeric peptide with enhanced cell specificity and anti-inflammatory activity

An antimicrobial peptide (AMP), Hn-Mc, was designed by combining the N-terminus of HPA3NT3 and the C-terminus of melittin. This chimeric AMP exhibited potent antibacterial activity with low minimal inhibitory concentrations (MICs), ranging from 1 to 2 μM against four drug-susceptible bacteria and ten drug-resistant bacteria. Moreover, the hemolysis and cytotoxicity was reduced significantly compared to those of the parent peptides, highlighting its high cell selectivity. The morphological changes in the giant unilamellar vesicles and bacterial cell surfaces caused by the Hn-Mc peptide suggested that it killed the microbial cells by damaging the membrane envelope. An in vivo study also demonstrated the antibacterial activity of the Hn-Mc peptide in a mouse model infected with drug-resistant bacteria. In addition, the chimeric peptide inhibited the expression of lipopolysaccharide (LPS)-induced cytokines in RAW 264.7 cells by preventing the interaction between LPS and Toll-like receptors. These results suggest that this chimeric peptide is an antimicrobial and anti-inflammatory candidate as a pharmaceutic agent.

RGD-mimetic poly(amidoamine) hydrogel for the fabrication of complex cell-laden micro constructs

The potential of the 3D cell culture approach for creating in vitro models for drug screening and cellular studies, has led to the development of hydrogels that are able to mimic the in vivo 3D cellular milieu. To this aim, synthetic polymer-based hydrogels, with which it is possible to fine-tune the chemical and biophysical properties of the cell microenvironment, are becoming more and more acclaimed. Of all synthetic materials, poly(amidoamine)s (PAAs) hydrogels are known to have promising properties. In particular, PAAs hydrogels containing the 2,2-bisacrylamidoacetic acid-agmatine monomeric unit are capable of enhancing cellular adhesion by interacting with the RGD-binding αVβ3 integrin. The synthesis of a new photocrosslinkable, biomimetic PAA-Jeffamine®-PAA triblock copolymer (PJP) hydrogel is reported in this paper with the aim of improving the optical, biocompatibility and cell-adhesion properties of previously studied PAA hydrogels and providing an inexpensive alternative to the RGD peptide based hydrogels. The physicochemical properties of PJP hydrogels are extensively discussed and the behavior of 2D and 3D cell cultures was analyzed in depth with different cell types. Moreover, cell-laden PJP hydrogels were patterned with perfusable microchannels and seeded with endothelial cells, in order to investigate the possibility of using PJP hydrogels for fabricating cell laden tissue-like micro constructs and microfluidic devices. Overall the data obtained suggest that PJP could ultimately become a useful tool for fabricating improved in vitro models in order to potentially enhance the effectiveness of drug screening and clinical treatments.

Polyamidoamine and polyglycerol; their linear, dendritic and linear–dendritic architectures as anticancer drug delivery systems

This review covers the latest advances in the conjugation of chemotherapeutics such as doxorubicin, paclitaxel, methotrexate, fluorouracil and cisplatin to dendritic polymers, including polyamidoamine dendrimers, hyperbranched polyglycerols and their linear analogues, with a focus on their cytotoxicity, biodistribution and biodegradability.

Cationic Polymers for Intracellular Delivery of Proteins

Many therapeutic proteins exert their pharmaceutical action inside the cytoplasm or onto individual organelles inside the cell. Intracellular protein delivery is considered to be the most direct, fastest and safest approach for curing gene-deficiency diseases, enhancing vaccination and triggering cell transdifferentiation processes, within other curative applications. However, several hurdles have to be overcome. For this purpose the use of polymers, with their ease of modification in physical and chemical properties, is attractive in protein drug carriers. They can protect their therapeutic protein cargo from degradation and enhance their bioavailability at targeted sites. In this chapter, potential and currently used polymers for fabrication of protein delivery systems and their applications for intracellular administration are discussed. Special attention is given to the use of cationic polymers for their ability to promote the cellular uptake of therapeutic proteins.

Poly(amido-amine)-based hydrogels with tailored mechanical properties and degradation rates for tissue engineering

Poly(amido-amine) (PAA) hydrogels containing the 2,2-bisacrylamidoacetic acid-4-amminobutyl guanidine monomeric unit have a known ability to enhance cellular adhesion by interacting with the arginin-glycin-aspartic acid (RGD)-binding αVβ3 integrin, expressed by a wide number of cell types. Scientific interest in this class of materials has traditionally been hampered by their poor mechanical properties and restricted range of degradation rate. Here we present the design of novel biocompatible, RGD-mimic PAA-based hydrogels with wide and tunable degradation rates as well as improved mechanical and biological properties for biomedical applications. This is achieved by radical polymerization of acrylamide-terminated PAA oligomers in both the presence and absence of 2-hydroxyethylmethacrylate. The degradation rate is found to be precisely tunable by adjusting the PAA oligomer molecular weight and acrylic co-monomer concentration in the starting reaction mixture. Cell adhesion and proliferation tests on Madin-Darby canine kidney epithelial cells show that PAA-based hydrogels have the capacity to promote cell adhesion up to 200% compared to the control. Mechanical tests show higher compressive strength of acrylic chain containing hydrogels compared to traditional PAA hydrogels.

Role of integrated cancer nanomedicine in overcoming drug resistance

Cancer remains a major killer of mankind. Failure of conventional chemotherapy has resulted in recurrence and development of virulent multi drug resistant (MDR) phenotypes adding to the complexity and diversity of this deadly disease. Apart from displaying classical physiological abnormalities and aberrant blood flow behavior, MDR cancers exhibit several distinctive features such as higher apoptotic threshold, aerobic glycolysis, regions of hypoxia, and elevated activity of drug-efflux transporters. MDR transporters play a pivotal role in protecting the cancer stem cells (CSCs) from chemotherapy. It is speculated that CSCs are instrumental in reviving tumors after the chemo and radiotherapy. In this regard, multifunctional nanoparticles that can integrate various key components such as drugs, genes, imaging agents and targeting ligands using unique delivery platforms would be more efficient in treating MDR cancers. This review presents some of the important principles involved in development of MDR and novel methods of treating cancers using multifunctional-targeted nanoparticles. Illustrative examples of nanoparticles engineered for drug/gene combination delivery and stimuli responsive nanoparticle systems for cancer therapy are also discussed.

Bioresponsive poly(amidoamine)s designed for intracellular protein delivery

Poly(amidoamine)s with bioreducible disulfide linkages in the main chain (SS-PAAs) and pH-responsive, negatively charged citraconate groups in the sidechain have been designed for effective intracellular delivery and release of proteins with a net positive charge at neutral pH. Using lysozyme as a cationic model protein these water soluble polymers efficiently self-assemble into nanocomplexes by charge attraction. At pH5 (the endosomal pH) the amide linkages connecting the citraconate groups in the sidechains of the SS-PAAs are hydrolyzed by intramolecular catalysis, resulting in expulsion of the negative citraconate groups and formation of protonated amine groups, resulting in charge reversal of the polymeric carrier from negative to positive. The concomitant endosomal buffering effect and increased polymer-endosomal membrane interactions are considered to lead to increased protein delivery into the cytosol. Besides destabilization of the polymer-protein nanoparticles by the charge reversal effect, intracellular cleavage of disulfide linkages in the polymer ensure further unpacking of the protein in the cytosol. Cellinternalization and cytotoxicity experiments with primary human umbilical vein endothelial cells (HUVEC) showed that the SS-PAA-based nanocomplexes were essentially non-toxic, and that lysozyme is successfully internalized into HUVEC. The results indicate that these charge reversal SS-PAAs have excellent properties as non-toxic intracellular delivery systems for cationic proteins.

Synergistic antitumor activity from two-stage delivery of targeted toxins and endosome-disrupting nanoparticles

Plant-derived Type I toxins are candidate anticancer therapeutics requiring cytosolic delivery into tumor cells. We tested a concept for two-stage delivery, whereby tumor cells precoated with an antibody-targeted gelonin toxin were killed by exposure to endosome-disrupting polymer nanoparticles. Co-internalization of particles and tumor cell-bound gelonin led to cytosolic delivery and >50-fold enhancement of toxin efficacy. This approach allows the extreme potency of gelonin to be focused on tumors with significantly reduced potential for off-target toxicity.

Biological stimuli and biomolecules in the assembly and manipulation of nanoscale polymeric particles

Living systems are replete with complex, stimuli-responsive nanoscale materials and molecular self-assemblies. There is an ever increasing and intense interest within the chemical sciences to understand, mimic and interface with these biological systems utilizing synthetic and/or semi-synthetic tools. Our aim in this review is to give perspective on this emerging field of research by highlighting examples of polymeric nanoparticles and micelles that are prepared utilizing biopolymers together with synthetic polymers for the purpose of developing nanomaterials capable of interacting and responding to biologically relevant stimuli. It is expected that with the merging of evolved biological molecules with synthetic materials, will come the ability to prepare complex, functional devices. A variety of applications will become accessible including self-healing materials, self-replicating systems, biodiagnostic tools, drug targeting materials and autonomous, adaptive sensors. Most importantly, the success of this type of strategy will impact how biomolecules are stabilized and incorporated into synthetic devices and at the same time, will influence how synthetic materials are utilized within biomedical applications.

Interaction of melittin peptides with perfluorocarbon nanoemulsion particles

Melittin, an antimicrobial peptide, forms pores in biological membranes and triggers cell death. Therefore, it has potential as an anticancer therapy. However, until recently, the therapeutic application of melittin has been impractical because a suitable platform for delivery was not available. Recently, we showed that phospholipid-stabilized perfluorooctyl bromide based nanoemulsion particles (PFOB-NEPs) were resistant to destruction by melittin and enabled specific delivery of melittin to tumor cells, killing them and reducing tumor growth. Earlier, prior work also showed that melittin adsorbed onto the stabilizing phospholipid monolayer of PFOB-NEP but did not disrupt the phospholipid monolayer or produce "cracking" of the PFOB-NEPs. The present work identifies the important structural motifs for melittin binding to PFOB-NEPs through a series of atomistic molecular dynamics simulations. The conformational ensemble of melittin bound to PFOB-NEP lipid monolayer was compared to structure from a control simulation of melittin bound to a lipid bilayer to identify several differences in melittin-lipid interactions between the two systems. First, melittin was deeply buried in the hydrophobic tail region of bilayer, while its depth was attenuated in the PFOB-NEP monolayer. Second, a helical conformation was the major secondary structure in the bilayer, but the fraction of helix was reduced in the PFOB-NEP. Finally, the overall pattern for the direct interaction of melittin with surrounding lipids was similar between liposome and PFOB-NEP, but the level of interaction was slightly decreased in the PFOB-NEP. These results suggest that melittin interacts with the monolayer of PFOB-NEP in a way that is similar way to its interaction with bilayers but that deeper penetration into the hydrophobic interior is inhibited.

Tumor delivery of macromolecular drugs based on the EPR effect

Enhanced permeability and retention (EPR) effect is the physiology-based principal mechanism of tumor accumulation of large molecules and small particles. This specific issue of Advanced Drug Delivery Reviews is summing up multiple data on the EPR effect-based drug design and clinical outcome. In this commentary, the role of the EPR effect in the intratumoral delivery of protein and peptide drugs, macromolecular drugs and drug-loaded long-circulating pharmaceutical nanocarriers is briefly discussed together with some additional opportunities for drug delivery arising from the initial EPR effect-mediated accumulation of drug-containing macromolecular systems in tumors.

Functionalized linear poly(amidoamine)s are efficient vectors for intracellular protein delivery

An effective intracellular protein delivery system was developed based on functionalized linear poly(amidoamine)s (PAAs) that form self-assembled cationic nanocomplexes with oppositely charged proteins. Three differently functionalized PAAs were synthesized, two of these having repetitive disulfide bonds in the main chain, by Michael-type polyaddition of 4-amino-1-butanol (ABOL) to cystamine bisacrylamide (CBA), histamine (HIS) to CBA, and ABOL to bis(acryloyl)piperazine (BAP). These water-soluble PAAs efficiently condense β-galactosidase by self-assembly into nanoscaled and positively-charged complexes. Stable under neutral extracellular conditions, the disulfide-containing nanocomplexes rapidly destabilized in a reductive intracellular environment. Cell-internalization and cytotoxicity experiments showed that the PAA-based nanocomplexes were essentially non-toxic. β-Galactosidase was successfully internalized into cells, with up to 94% of the cells showing β-galactosidase activity, whereas the enzyme alone was not taken up by the cells. The results indicate that these poly(amidoamine)s have excellent properties as highly potent and non-toxic intracellular protein carriers, which should create opportunities for novel applications in protein delivery.

PEGylation of Melittin: Structural Characterization and Hemostatic Effects

To promote and understand the structure—property relationship for hemostasis, we modified melittin (MLT) using a four-arm poly(ethylene glycol) (PEG) with N-hydroxysuccinimide ester. The PEGylation was characterized by FTIR, MALDI-MS, NMR, a bicinchoninic acid assay, circular dichroism, hemolysis assay, and thromboelastography. Changes in the reaction conditions affected the extent of the modification, the numbers of MLT conjugated to PEG arms, and possible PEGylation sites. The reaction at pH 9.2 with a high MLT/PEG ratio, resulted in the highest modification. Reactions in dimethylsulfoxide (DMSO) resulted in more multi-arm coupled MLT, reaching a maximum of four MLT per PEG. The helicity of the modified peptide, relative to the native peptide, was essentially maintained in DMSO, but substantially lost at pH 9.2. PEGylation reduced the hemolytic effects of MLT and subsequently changed its coagulation profiles. The overall hemostatic effects of MLT modified in DMSO indicate that this may be a convenient approach to the PEGylation of biomolecules for biomedical applications.

Poly(amidoamine) conjugates containing doxorubicin bound via an acid-sensitive linker

Poly(amidoamine)s with amino pendant groups were prepared by hydrogen-transfer polyaddition of primary and secondary amines to bis-acrylamines. Dansyl cadaverine (DC) doxorubicin (Dox) were bound to the polymers via a cis-aconityl spacer to give conjugates containing 3 microg of DC per mg of polymer and 28 to 35 microg of Dox per mg of polymer. Release of DC and Dox at physiological and acidic pH varied from 0 to 35% over 48 h and was pH dependent. Although the ISA1Dox conjugate (IC(50) = 6 microg Dox x mL(-1)) presented similar toxicity as the parent polymer without Dox, ISA23Dox showed increased toxicity (IC(50) = 10 microg Dox x mL(-1)). These results suggest that ISA23Dox is able to release biologically active Dox in vitro and that this conjugate might be suitable for further development.

Biomimetic poly(amidoamine) hydrogels as synthetic materials for cell culture

Background

Poly(amidoamine)s (PAAs) are synthetic polymers endowed with many biologically interesting properties, being highly biocompatible, non toxic and biodegradable. Hydrogels based on PAAs can be easily modified during the synthesis by the introduction of functional co-monomers. Aim of this work is the development and testing of novel amphoteric nanosized poly(amidoamine) hydrogel film incorporating 4-aminobutylguanidine (agmatine) moieties to create RGD-mimicking repeating units for promoting cell adhesion.

Results

A systematic comparative study of the response of an epithelial cell line was performed on hydrogels with agmatine and on non-functionalized amphoteric poly(amidoamine) hydrogels and tissue culture plastic substrates. The cell adhesion on the agmatine containing substrates was comparable to that on plastic substrates and significantly enhanced with respect to the non-functionalized controls. Interestingly, spreading and proliferation on the functionalized supports are slower than on plastic exhibiting the possibility of an easier control of the cell growth kinetics. In order to favor the handling of the samples, a procedure for the production of bi-layered constructs was also developed by means the deposition via spin coating of a thin layer of hydrogel on a pre-treated cover slip.

Conclusion

The obtained results reveal that PAAs hydrogels can be profitably functionalized and, in general, undergo physical and chemical modifications to meet specific requirements. In particular the incorporation of agmatine warrants good potential in the field of cell culturing and the development of supported functionalized hydrogels on cover glass are very promising substrates for applications in cell screening devices.

Melittin: a membrane-active peptide with diverse functions

Melittin is the principal toxic component in the venom of the European honey bee Apis mellifera and is a cationic, hemolytic peptide. It is a small linear peptide composed of 26 amino acid residues in which the amino-terminal region is predominantly hydrophobic whereas the carboxy-terminal region is hydrophilic due to the presence of a stretch of positively charged amino acids. This amphiphilic property of melittin has resulted in melittin being used as a suitable model peptide for monitoring lipid-protein interactions in membranes. In this review, the solution and membrane properties of melittin are highlighted, with an emphasis on melittin-membrane interaction using biophysical approaches. The recent applications of melittin in various cellular processes are discussed.

Temperature- and pH-responsive smart polymers for gene delivery

Biopolymer therapeutics are likely to be the next generation of medicines, and nucleic acids are among the most important of these potential drugs. The challenges of delivering genes are formidable and advanced biomimetic materials are expected to be required. Polymers that can respond to changes in temperature and pH are good candidates for gene delivery vehicles, as the stimulus response can be used to alter their interactions with the drug payload. In this review, the chemistries underlying these responsive polymers are considered, and the possible mechanisms by which nucleic acids, primarily DNA, can be protected during transit and released at target sites are outlined. Sophisticated multicomponent polymers are being developed, with functionalities designed to overcome the barriers to gene delivery at both the systemic and local level; key examples are highlighted. The extension of these materials to yet more advanced therapies, such as cell delivery and regenerative medicine, is outlined as an emerging technology for the future.

Study of the interaction between Apis mellifera venom and micro-heterogeneous systems

The bee venom, used in treatment of inflammatory and articular diseases, is a complex mixture of peptides and enzymes and the presence of tryptophan allows the investigation by fluorescence techniques. Steady state and time-resolved fluorescence spectroscopy were used to study the interaction between bee venom extracted from Apis mellifera and three micro heterogeneous systems: sodium dodecylsulphate (SDS) micelles, sodium dodecylsulphate-poly(ethylene oxide) (SDS-PEO) aggregates, and the polymeric micelles LUTROL F127, formed by poly(ethylene oxide)-poly(propylene oxide)- poly(ethylene oxide). Fluorescence parameters in buffer solution were typical of peptides containing tryptophan exposed to the aqueous medium, and they gradually changed upon the addition of surfactant and polymeric micelles, demonstrating the interaction of the peptides with the micro heterogeneous systems. Quenching experiments were carried out using the N-alkylpyridinium ions (ethyl, hexyl, and dodecyl) as quenchers. In buffer solution the quenching has low efficiency and is independent of the alkyl chain length of the quencher. In the presence of the micro heterogeneous systems the extent of static and dynamic quenching enhanced, showing that both fluorophore and quenchers reside in the microvolume of the aggregates. The more hydrophobic quencher (dodecyl pyridinium ion) provides higher values for K (SV) and dynamic quenching constants, and SDS-PEO aggregates are most efficient to promote interaction between peptides and alkyl pyridinium ions. The results proved that bee venom interacts with drug delivery micelles of the copolymer LUTROL F127.