Dendrimer Cavities Research Articles

Polyamidoamine Dendrimers Functionalized with ZnO-Chitosan Nanoparticles as an Efficient Surface for L-asparaginase Immobilization.

In this study, the third-generation polyamidoamine dendrimer was functionalized with a 5-amino-1H-tetrazole heterocycle to load the synthesis enzyme and its surface groups. Then, chitosan was attached to the dendrimer by a suitable linker, and finally, zinc oxide nanoparticles were inserted into dendrimer cavities to increase loading. FTIR, FESEM, TEM, and DLS analysis showed that this new dendrimer has specific branches, and ZnO nanoparticles were spread between the branches and connected with the branches and chitosan biopolymer. Also proved the presence of stabilized L-asparaginase enzyme and ZnO nanoparticles in the designed system. Furthermore, the extent of L-asparaginase enzyme loading and release was investigated in the laboratory with a dialysis bag. Examining the toxicity of the new third-generation polyamidoamine (PAMAM) dendrimeric nanocarrier based on chitosan-zinc oxide biopolymer (PAMAM-G3@ZnO-Cs nanocarrier) on the Jurkat cell line (human acute lymphoblastic leukemia) at pH 7.4 showed that this nanocarrier effectively encapsulates the drug L-asparaginase and slowly releases it and also preventing the growth of cancer cells. The activity of the loaded enzyme in the nanocarrier and the free enzyme was calculated. During the investigations, it was found that the enzyme attached to the nanocarrier is more stable than the free enzyme at optimal pH and temperature and at high temperatures, acidic and basic pHs. Vmax and Km values were lower for loaded enzymes. The synthesized PAMAM-G3@ZnO-Cs nanocarrier can be a promising candidate in the pharmaceutical industry and medical science for cancer treatment due to its biocompatibility, non-toxicity, stability, and slow release of L-asparaginase.

New method of identifying morphine in urine samples using nanoparticle-dendrimer-enzyme hybrid system

The incorporation of morphine (MOR) into the nanoparticle structure is a viable alternative to traditional enzyme usage. It has good biological potential to separate MOR from real urine samples. In this study, a new method of MOR identification in real urine samples was synthesized using the β-glucuronidase-dendrimer poly amidoamine (PAMAM) enzyme hybrid system. Replacing MOR in dendrimer cavities significantly reduces enzyme consumption. The replacement technique is done in dendrimer cavities in two stages as an alternative to β-glucuronidase enzyme and even MOR. In this paper, firstly, PAMAM dendrimer G2 was synthesized based on silica. The β-glucuronidase enzyme was replaced inside its dendrimer cavities and the compound was released into a real urine sample containing MOR. The enzyme was extracted from dendrimer cavities. The MOR- β-glucuronidase enzyme bond broke. In the next stage of the process, free MOR entered the PAMAM dendrimer G2 cavities. MOR was detected in real urine samples.

Host-guest complexation of curcumin and coumarin 6 with PAMAM-OH: Insight from fluorescence spectroscopy and molecular dynamics simulations

The 1:1 host-guest association between hydroxyl-terminated poly(amido amine) dendrimers of the fourth generation (G4-PAMAM-OH) and two model fluorescent dyes, curcumin (CUR) and coumarin 6 (CU6), was studied from fluorescence intensity experiments and fully atomistic molecular dynamics (MD) simulations. Our results account for experimental binding constants of 3.45 × 105 and 2.97 × 105 mol−1L for CUR-G4-PAMAM-OH and CU6-G4-PAMAM-OH systems, respectively. The potential of dendrimer complexation to increase dye photostability was evaluated from fluorescence intensity experiments in 5–100 μmol L−1 dye solutions containing 100 μmol L−1 of G4-PAMAM-OH under visible light irradiation. Our results revealed that G4-PAMAM-OH enhances the photostability of CUR at 1:1, 1:2 and 1:20 dye-dendrimer ratios, whereas CU6 is effectively protected only at 1:20 dendrimer excess conditions. MD simulations predicted a deep encapsulation of CUR within innermost dendrimer branches and an outer association of CU6 to surface dendrimer cavities, which can be related to the enhanced photoprotection of CUR at lower dye-dendrimer ratios. MM/GBSA binding free energy estimates suggest the predominance of van der Waals interactions between apolar dye segments and hydrophobic dendrimer pockets as the main binding forces driving dye-dendrimer supramolecular association in the systems under study.

Amphiphilic Dendrimer as Reverse Micelle: Synthesis, Characterization and Application as Homogeneous Organocatalyst

The core and surface terminal groups are the two main catalytic sites in a dendrimer. In most of the reported examples, the catalytic sites in dendritic catalysis are the surface terminal functional groups. This perspective article concerned with the dendrimer based catalysis, involving these two catalytic sites and the dendrimer cavities. The interior cavities provide the nanoscale reactor sites, by creating reverse micelle like appearance for catalysis. In exploring the significant achievements in this area, a low generation PAMAM dendrimer with amphiphilic nature, having a polymeric core with large number of pendent amino groups was synthesized and concentrated its catalytic activity. The key features with respect to positive and/or negative catalytic activity was highlighted by synthesizing various aryl and heteroaryl 2-substituted benzimidazoles. The synthesized dendritic organocatalyst was proved to be amazingly reactive and gave high yield of products within a few minutes at room temperature with low catalyst loading. Here, a new stable hemiaminal, the species rarely been detected and much less isolated in bulk, was obtained during the synthesis of benzimidazoles. Moreover, this is the first reported method for the synthesis of benzimidazoles, using the homogeneous PAMAM dendrimer as a basic organocatalyst.

Effect of pH on Eosin Y/PAMAM interactions studied from absorption spectroscopy and molecular dynamics simulations

Absorption spectroscopy experiments were carried out to examine the 1:1 supramolecular interaction between Eosin Y (EOS) and low generation G0-G3 poly(amido amine) (PAMAM) dendrimers at neutral and basic media, aimed at gaining insight about the role of pH and dendrimer generation on EOS-PAMAM binding. Our results revealed that EOS complexation is favored under neutral pH conditions, and that the supramolecular interaction strengthens as the dendrimer generation increases. Further molecular-level information regarding EOS-PAMAM systems was obtained from Molecular Dynamics (MD) simulations, Non-Covalent Interaction (NCI) analysis and MM/PBSA binding free energy calculations, which were carried out to examine the role of the generation, charge, and protonation state of PAMAM on the structure, conformation, and preferable interactions with EOS at neutral and basic pH conditions. Theoretical predictions were in high agreement with experimental results, showing that neutral pH allows a faster, deeper, and more stable complexation of the dye within dendrimer cavities, and that higher generation dendrimers induce a larger affinity towards EOS. According to MD results, the binding mode of the dye favors the interaction of the xanthene moiety within internal dendrimer cavities through the establishment of attractive van der Waals contacts. On the other hand, the carboxylate moiety interacts with the outermost dendrimer branches and remains exposed towards the solvent in G0-G2 PAMAM. These results support the validity of using MD simulations as auxiliary tools to deal with supramolecular complexation phenomena involving PAMAM dendrimers as host molecules.

A computational study of PAMAM dendrimer interaction with trans isomer of picoplatin anticancer drug

In this study, the interaction of zero generation (G0) of polyamidoamine (PAMAM) dendrimer with trans isomer of Picoplatin anticancer drug (AMD) has been investigated by density functional theory. According to the structure of dendrimer and drug, two types of dendrimer cavities that can interact with the drugs can be formed in drug-loaded PAMAM dendrimer in which AMD drug can be located inside the PAMAM cavities through Cl and NH3 heads. The results have indicated that the interaction of PAMAM dendrimer with picoplatin anticancer drugs is physisorption. Relevant information about geometry, adsorption energy and molecular orbitals and quantum molecular descriptor, the most stable site for drug loading corresponds to the core of the dendrimer. The PAMAM-AMD complexes have shown a significant improvement of structural and electronic properties according to the results obtained from different arrangement of PAMAM G0-AMD complexes; a [G0-AMD (Cl-1)] complex is the preferred adsorption arrangement. As a result, it seems that the zero generation PAMAM dendrimer being combined with the AMD drug is suitable for use in drug delivery.

Partially PEGylated PAMAM dendrimers as solubility enhancers of Silybin

PEGylated PAMAM-G4 dendrimers with substitution percentages of 50% and intermediate size PEG chains (0.55 and 2.0 kDa) were synthesized and evaluated as solubility enhancers and potential supramolecular carriers for the poorly soluble drug Silybin (SIL). Aqueous solubility profiles revealed that the PEGylated system with 2.0 kDa chains induced a five-fold solubility increase for SIL and the largest drug-loading capacity within the systems under study with an average complex stoichiometry of 71:1 according to the Higuchi–Connors formulation for multiple binding sites. The supramolecular interaction between SIL and PEGylated PAMAM-G4 dendrimers was confirmed by 2D-NOESY experiments, which evidenced the simultaneous complexation of the drug in both PAMAM-G4 branches and outermost PEG chains. In vitro release studies showed that 2.0 kDa PEG chains induced a more extended release time compared with 0.5 kDa PEG chains. This result was attributed to the enhancement of PEG assistance to SIL complexation in systems with longer PEG chains, which are able to self-penetrate into dendrimer cavities and cooperate in the stabilization of SIL complexes, thus delaying the release of SIL from the supramolecular host. These results are valuable for the future design and development of novel PAMAM-based systems for SIL complexation and delivery.

Synthesis and characterization of poly(propylene imine)-dendrimer-grafted gold nanoparticles as nanocarriers of doxorubicin

The aim of current work is synthesis 4th-generation-poly(propylene imine) (PPI)-dendrimer modified gold nanoparticles (Au-G4A) as nanocarriers for doxorubicin (DOX) and studying in vitro drug release kinetics from nanocarriers into different media. Accordingly, AuNPs were synthesized by reduction of chloroauric acid (HAuCl4) aqueous solution with trisodium citrate and modified with cysteamine to obtain amine-functionalized (Au-NH2) nanoparticles. Au-NH2 nanoparticles were used as multifunctional cores and participated in Michael addition of acrylonitrile and reduction process by lithium aluminum hydride (LAH) to synthesize Au-G4A nanoparticles. Also, peripheral primary amine groups of Au-G4A were conjugated with folic acid (FA) (Au-G4F) to study the bioconjugation effect on drug release behavior of nanostructures. Ultraviolet spectroscopy (UV–vis), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) were used to approve the synthesis of different nanostructures. Finally, Au-G4A and Au-G4F samples were loaded with DOX and exposed to environments with different pH values to examine the release properties of nanostructures. Also, drug release kinetics was investigated by fitting of experimental data with different release models. As a result, synthesized dendritic structures showed Higuchi and Korsmeyer-Peppas models release behavior due to better solubility of drug in release media with respect to dendrimer cavities and drug release through polymeric matrix respectively.

Synthesis of poly(propylene imine) dendrimers via homogeneous reduction process using lithium aluminium hydride: Bioconjugation with folic acid and doxorubicin release kinetics

The heterogeneous reduction process for synthesis of poly(propylene imine) (PPI) dendrimer has been replaced by a novel and homogeneous process. Accordingly, to prepare half generations, acrylonitrile was added to amine groups via Michael addition reaction. Then, nitrile groups were reduced via homogeneous hydrogenation using lithium aluminium hydride to synthesize fifth‐generation PPI dendrimers with ethylenediamine core. Also, peripheral primary amine groups were conjugated with folic acid (FA). Fourier transform infrared and 13C NMR spectroscopies and gel permeation chromatograph y were used to prove the synthesis of the various structures. Finally fifth‐generation and FA‐conjugated fifth‐generation PPI dendrimers were loaded with doxorubicin and exposed to environments with different pH values to examine the release properties of the structures. Also, drug release kinetics was investigated by fitting experimental data with various release models. The synthesized dendritic structures showed Higuchi model release behaviour due to better solubility of drug in release media with respect to dendrimer cavities.

Multifunctional Nanoplatform for Targeted Laser-induced Hyperthermia and Microscopy of Breast Cancer Cells using SPION-based Gold and Folic Acid Conjugated Nanodendrimers: An in vitro Assay

The use of nanotechnology seems to be a promising approach for early detection, imaging and therapy of cancer. In this investigation, 9 nm superparamagnetic iron oxide nanoparticles (SPION) were synthesized and functionalized by third generation polyamidoamine (G3-PAMAM) dendrimer. The magnetodendrimer samples were then conjugated by folic acid molecules for targeting and by gold nanoparticles for photothermal hyperthermia purpose. The gold nanoparticles were synthesized using three reducing agents of sodium borohydride, hydrazine sulfate and presynthesized 10-nm AuNPs. The final nanocomposite is named IDAF NC (Iron oxide-Dendrimer-Gold-Folic acid). Two breast cancer cell lines of MDA MB 231 and MCF 7 were used for cytotoxicity, uptake and photothermal assay. The results confirmed that AuNPs prepared by sodium borohydrate and the pre-synthesized 10-nm AuNPs were larger and those prepared by hydrazine sulfate were smaller and uniformly entrapped within dendrimer cavities. The MDA MB 231-IDAF-Hydr combination exhibited the highest viability percentage at 50 μg/mL before laser irradiation and lowest cancer cell viability of 65% (i.e., highest cell apoptosis and crystallization after irradiation).

Catalytic Behavior of Different Sizes of Dendrimer-Encapsulated Aun Nanoparticles in the Oxidative Degradation of Morin with H2O2

Different sizes of icosahedral-like dendrimer-encapsulated Au nanoparticles (Au55- and Au147-DENs) were prepared in the presence of generation 6 amine-terminated dendrimers (G6-PAMAM-NH2) as a template. The synthesis is carried out by the complexation of a Au metal precursor (AuHCI4) with the tertiary amine groups within the dendrimer framework. The addition of excess reducing agent, NaBH4, results in the formation of Au nanoparticles encapsulated within the dendrimer cavities. The as-prepared catalysts were characterized using UV-visible (UV-vis) spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray analysis (EDX), and Fourier transform infrared (FTIR). The average sizes of Au55- and Au147-DENs were determined to be 1.7 ± 0.4 and 2.0 ± 0.3 nm, respectively. The catalytic activity of these Au-DEN catalysts was evaluated in the oxidative decomposition of morin by H2O2. Since morin has a maximum absorption band at λ 410 nm at pH 10, this catalyzed oxidation process was monitored by time-resolved UV-vis spectroscopy. The catalytic activities of these two catalysts were compared by fitting the kinetic data to the Langmuir-Hinshelwood model. This model allows the determination of adsorption constants of both morin (K(morin)) and H2O2 (K(H2O2)) on the catalyst surface. A full kinetic study for this Au-DEN-catalyzed oxidative degradation of morin is reported.

Evidence of guest encapsulation within G8 and G10 dendrimers using NMR techniques.

Encapsulation of guest molecules within the interior cavities of dendrimers is promising, but high generation dendrimers show limited encapsulation capacity due to their dense surface shell. Here, for the first time, we prove that high generation polyamidoamine dendrimers, such as generation 8 and generation 10, are able to encapsulate hydrophobic guests using NMR spectroscopy. Guest molecules such as phenylbutazone, dexamethasone sodium phosphate and 9-anthracenecarboxylic acid with molecular weights up to 516 Da are in close proximity to the interior scaffold protons of high generation dendrimers. This encapsulation behavior depends on guest hydrophobicity. Chemical defects and back-folding of terminal groups make it possible for these guest molecules to penetrate through the dense surface shell of high generation dendrimers. These results provide new insights into the host-guest chemistry of dendrimers.

Drug-dendrimer supramolecular complexation studied from molecular dynamics simulations and NMR spectroscopy

Fully atomistic molecular dynamics (MD) simulations and NMR spectroscopy were employed to get insights about the molecular details of drug-dendrimer supramolecular association phenomena, using piroxicam (PRX) and the third generation poly(amido amine) (PA- MAM-G3) dendrimer as model systems. Theoretical results concerning the complex stoichiometry suggest that PRX forms drug-dendrimer complexes of the type 24:1 at pH 7.0. This result was validated with the experimental quantities obtained from aqueous solubility profiles, which led to an empiric stoichiometry of 23:1 for the PRX:PA- MAM-G3 system. The predicted binding mode between PRX and PAMAM-G3 accounts for the preferred encap- sulation of the drug inside dendrimer cavities, which is mainly driven by van der Waals and hydrogen bonding interactions, and to a lesser extent, for the external asso- ciation of the guest through electrostatic contacts with the positively charged amino groups of PAMAM periphery. The binding mode obtained from MD simulations was confirmed with 2D-NOESY experiments, which evidence the preferred internal complexation of PRX with PAMAM- G3. The predominance of internal encapsulation over external contacts in the PRX:PAMAM-G3 system differs from the general behaviour expected for acidic anionic guests, for which external electrostatic interactions with the positively charged PAMAM surface have been postulated as the most relevant factor for drug association.

Complexation of Mefenamic Acid by Low‐Generation PAMAM Dendrimers: Insight from NMR Spectroscopy Studies and Molecular Dynamics Simulations

The complexation of mefenamic acid (MA) with poly(amido amine) dendrimers of the second and third generation (PAMAM‐G2 and PAMAM‐G3) at pH 7.0 is studied by aqueous solubility experiments, DOSY and 2D‐NOESY spectroscopy, and fully atomistic molecular dynamics (MD) simulations. Solubility profiles account for the formation of MA:PAMAM complexes of the type 10:1 and 15:1, for PAMAM‐G2 and PAMAM‐G3, respectively, with a maximum solubilization enhancement of 14.6 mol of MA per mol dendrimer. Diffusion ordered sepectroscopy (DOSY) and nuclear Overhauser effect spectroscopy (NOESY) experiments suggest that MA association occurs through both external electrostatic interactions with the PAMAM surface and internal encapsulation into the deep dendrimer cavities. MD simulations are consistent with these experimental findings and show that the internal drug encapsulation is enhanced as the dendrimer generation increases. The involvement of internal and external interactions in the complexation of MA with low‐generation PAMAM dendrimers differs from the general behavior expected for acidic anionic guests, for which external electrostatic contacts with the positively charged PAMAM surface have been postulated as the most relevant factor for drug association. image

Biodegradable Polydisulfide Dendrimer Nanoclusters as MRI Contrast Agents

Gadolinium-conjugated dendrimer nanoclusters (DNCs) are a promising platform for the early detection of disease; however, their clinical utility is potentially limited due to safety concerns related to nephrogenic systemic fibrosis (NSF). In this paper, biodegradable DNCs were prepared with polydisulfide linkages between the individual dendrimers to facilitate excretion. Further, DNCs were labeled with premetalated Gd chelates to eliminate the risk of free Gd becoming entrapped in dendrimer cavities. The biodegradable polydisulfide DNCs possessed a circulation half-life of >1.6 h in mice and produced significant contrast enhancement in the abdominal aorta and kidneys for as long as 4 h. The DNCs were reduced in circulation as a result of thiol-disulfide exchange, and the degradation products were rapidly excreted via renal filtration. These agents demonstrated effective and prolonged in vivo contrast enhancement and yet minimized Gd tissue retention. Biodegradable polydisulfide DNCs represent a promising biodegradable macromolecular MRI contrast agent for magnetic resonance angiography and can potentially be further developed into target-specific MRI contrast agents.

Host–Guest Chemistry of Dendrimer–Cyclodextrin Conjugates: Selective Encapsulations of Guests within Dendrimer or Cyclodextrin Cavities Revealed by NOE NMR Techniques

In this study, G5 PAMAM dendrimer and α-, β-, γ-cyclodextrin (CD) conjugates were synthesized. Host-guest behaviors of the conjugates toward five guest molecules including sodium methotrexate (MTX), amantadine hydrochloride (ADH), sulfamethoxazole (SMZ), sodium deoxycholate (SDC), and sodium dodecyl sulfate (SDS) were analyzed by NOE NMR techniques. Among the five guest molecules, ADH only binds with β-CD in G5-β-CD, SDC shows higher priority to localize within the cavity of γ-CD in G5-γ-CD, while MTX exhibits selective encapsulation within the cavities of G5 dendrimer in G5-α-CD. SDS has high binding affinity with α-CD in G5-α-CD but forms a precipitate in the complex solution. SMZ shows simultaneous encapsulation within CDs (α-, β-, and γ-CD) or G5 in the presence of the three conjugates. The host behavior of G5-CD conjugates depends on CD cavity size, guest size, and hydrophobicity. The results obtained in this study are helpful in the optimization of dendrimer-CD conjugate-based drug delivery systems.

Host–Guest Chemistry of Dendrimer–Drug Complexes: 7. Formation of Stable Inclusions between Acetylated Dendrimers and Drugs Bearing Multiple Charges

Drug molecules bearing multiple charges usually form precipitates with cationic dendrimers, which presents a challenge during the preparation of dendrimer inclusions for these drugs. In the present study, fully acetylated polyamidoamine (PAMAM) dendrimers were proposed as stable vehicles for drug molecules bearing two negative charges such as Congo red and indocyanine green. NMR techniques including (1)H NMR and (1)H-(1)H NOESY were used to characterize the host-guest chemistry of acetylated dendrimer and these guest molecules. The cationic PAMAM dendrimer was found to form a precipitate with Congo red and indocyanine green, but the acetylated one avoided the formation of cross-linking structures in aqueous solutions. NOESY studies revealed the encapsulation of Congo red and indocyanine green within the interior cavities of PAMAM dendrimers at mild acidic conditions and acetylated dendrimers show much stronger ability to encapsulate the guest molecules than cationic ones. Also, UV-vis-NIR studies suggest that acetylated dendrimers significantly improve the photostability of indocyanine green and prevent the formation of indocyanine green J-aggregates in aqueous solutions. The present study provides a new insight into dendrimer-based host-guest systems, especially for those guest molecules bearing multiple charges.

Dynamic Internal Cavities of Dendrimers as Constrained Media. A Study of Photochemical Isomerizations of Stilbene and Azobenzene Using Poly(alkyl aryl ether) Dendrimers

Dendritic microenvironments defined by dynamic internal cavities of a dendrimer were probed through geometric isomerization of stilbene and azobenzene. A third-generation poly(alkyl aryl ether) dendrimer with hydrophilic exterior and hydrophobic interior was used as a reaction cavity in aqueous medium. The dynamic inner cavity sizes were varied by utilizing alkyl linkers that connect the branch junctures from ethyl to n-pentyl moiety (C(2)G3-C(5)G3). Dendrimers constituted with n-pentyl linker were found to afford higher solubilities of stilbene and azobenzene. Direct irradiation of trans-stilbene showed that C(5)G3 and C(4)G3 dendrimers afforded considerable phenanthrene formation, in addition to cis-stilbene, whereas C(3)G3 and C(2)G3 gave only cis-stilbene. An electron-transfer sensitized trans-cis isomerization, using cresyl violet perchlorate as the sensitizer, also led to similar results. Thermal isomerization of cis-azobenzene to trans-azobenzene within dendritic microenvironments revealed that the activation energy of the cis- to trans-isomer was increasing in the series C(5)G3 < C(4)G3 <C(3)G3 <C(2)G3. With the change in the alkyl linker from C(5) to C(2), significant changes in the activation parameters were observed.

Spatial distribution of intra-molecular water and polymeric components in polyelectrolyte dendrimers revealed by small angle scattering investigations

An experimental scheme using contrast variation small angle neutron scattering technique is developed to investigate the structural characteristics of amine-terminated poly(amidoamine) dendrimers solutions. Using this methodology, we present the dependence of both the intra-dendrimer water and the polymer distribution on molecular protonation, which can be precisely adjusted by tuning the pH of the solution. Assuming spherical symmetry of the spatial arrangement of the constituent components of dendrimer, and that the atomic ratio of hydrogen-to-deuterium for the solvent residing within the cavities of dendrimer is identical to that for the solvent outside the dendrimer, the intra-dendrimer water distribution along the radial direction is determined. Our result clearly reveals an outward relocation of the peripheral groups, as well as enhanced intra-dendrimer hydration, upon increasing the molecular protonation and, therefore, allows the determination of segmental backfolding in a quantitative manner. The connection between these charge-induced structural changes and our recently observed progressively active segmental dynamics is also discussed.

Interfacial Regions Governing Internal Cavities of Dendrimers. Studies of Poly(alkyl aryl ether) Dendrimers Constituted with Linkers of Varying Alkyl Chain Length

This report deals with a study of the properties of internal cavities of dendritic macromolecules that are capable of encapsulating and mediating photoreactions of guest molecules. The internal cavity structures of dendrimers are determined by the interfacial regions between the aqueous exterior and hydrocarbon like interior constituted by the linkers that connect symmetrically sited branch points constituting the dendrimer and head groups that cap the dendrimers. Phloroglucinol-based poly(alkyl aryl ether) dendrimers constituted with a homologous series of alkyl linkers were undertaken for the current study. Twelve dendrimers within first, second, and third generations, having ethyl, n-propyl, n-butyl, and n-pentyl groups as the linkers and hydroxyl groups at peripheries in each generation, were synthesized. Encapsulation of pyrene and coumarins by aqueous basic solutions of dendrimers were monitored by UV-vis and fluorescence spectroscopies, which showed that a lower generation dendrimer with an optimal alkyl linker presented better encapsulation abilities than a higher generation dendrimer. Norrish type I photoreaction of dibenzyl ketone was carried out within the above series of dendrimers to probe their abilities to hold guests and reactive intermediate radical pairs within themselves. The extent of cage effect from the series of third generation dendrimers was observed to be higher with dendrimers having an n-pentyl group as the linker.