Mass spectrometry of dendrimers.

Mass spectrometry (MS) has become an essential technique to characterize dendrimers as it proved efficient at tackling analytical challenges raised by their peculiar onion-like structure. Owing to their chemical diversity, this review covers benefits of MS methods as a function of dendrimer classes, discussing advantages and limitations of ionization techniques, tandem mass spectrometry (MS/MS) strategies to determine the structure of defective species, as well as most recently demonstrated capabilities of ion mobility spectrometry (IMS) in the field. Complementarily, the well-defined structure of these macromolecules offers major advantages in the development of MS-based method, as reported in a second section reviewing uses of dendrimers as MS and IMS calibration standards and as multifunctional charge inversion reagents in gas phase ion/ion reactions.

Engineering Ultrasoft Interactions in Stiff All-DNA Dendrimers by Site-Specific Control of Scaffold Flexibility.

A combined experimental and theoretical study of the structural correlations in moderately concentrated suspensions of all-DNA dendrimers of the second generation (G2) with controlled scaffold rigidity is reported here. Small-angle X-ray scattering experiments in concentrated aqueous saline solutions of stiff all-DNA G2 dendritic constructs reveal a novel anomalous liquid-like phase behavior which is reflected in the calculated structure factors as a two-step increase at low scattering wave vectors. By developing a new design strategy for adjusting the particle's internal flexibility based on site-selective incorporation of single-stranded DNA linkers into the dendritic scaffold, it is shown that this unconventional type of self-organization is strongly contingent on the dendrimer's stiffness. A comprehensive computer simulation study employing dendritic models with different levels of coarse-graining, and two theoretical approaches based on effective, pair-potential interactions, remarkably confirmed the origin of this unusual liquid-like behavior. The results demonstrate that the precise control of the internal structure of the dendritic scaffold conferred by the DNA can be potentially used to engineer a rich palette of novel ultrasoft interaction potentials that could offer a route for directed self-assembly of intriguing soft matter phases and experimental realizations of a host of unusual phenomena theoretically predicted for ultrasoft interacting systems.

Carboranylphosphines: B9-Substituted Derivatives with Enhanced Reactivity for the Anchoring to Dendrimers.

Several ortho-carboranes bearing a phenoxy or a phenylamino group in the B9 position were prepared employing various protection and deprotection strategies. Following established protocols, dendritic compounds were synthesized from a hexachlorocyclotriphosphazene or thiophosphoryl chloride core, and possible anchoring options for the B9-substituted ortho-carboranes were investigated experimentally and theoretically (DFT). Furthermore, 1- or 1,2-phosphanyl-substituted carborane derivatives were obtained. The resulting diethyl-, diisopropyl-, di-tert-butyl-, diphenyl- or diethoxyphosphines bearing a tunable ortho-carborane moiety are intriguing ligands for future applications in homogeneous catalysis or the medicinal sector.

Structural and Property Characterizations of Dual-Responsive Core-Shell Tecto Dendrimers for Tumor Penetration and Gene Delivery Applications.

Core-shell tecto dendrimers (CSTDs) with excellent physicochemical properties and good tumor penetration and gene transfection efficiency have been demonstrated to have the potential to replace high-generation dendrimers in biomedical applications. However, their characterization and related biological properties of CSTDs for enhanced tumor penetration and gene delivery still lack in-depth investigation. Herein, three types of dual-responsive CSTDs are designed for thorough physicochemical characterization and investigation of their tumor penetration and gene delivery efficiency. Three types of CSTDs are prepared through phenylborate ester bonds of phenylboronic acid (PBA)-decorated generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers as cores and monose (galactose, glucose, or mannose)-conjugated G3 PAMAM dendrimers as shells and thoroughly characterized via NMR and other techniques. It is shown that the produced CSTDs display strong correlation signals between the PBA and monose protons, similar hydrodynamic diameters, and dual reactive oxygen species- and pH-responsivenesses. The dual-responsive CSTDs are proven to have structure-dependent tumor penetration property and gene delivery efficiency in terms of small interference RNA for gene silencing and plasmid DNA for gene editing, thus revealing a great potential for different biomedical applications.

Homo and Hetero-Branched Lipopeptide Dendrimers: Synthesis and Antimicrobial Activity.

Di-branched and tetra-branched versions of a previously reported analogue of the lipopeptide battacin were successfully synthesised using thiol-maleimide click and 1, 2, 3-triazole click chemistry. Antimicrobial studies against drug resistant clinical isolates of Escherichia coli (ESBL E. coli Ctx-M14), Pseudomonas aeruginosa (P. aeruginosa Q502), and Methicillin resistant Staphylococcus aureus (MRSA ATCC 33593), as well as clinically isolated Acinetobacter baumannii (A. baumannii ATCC 19606), and P. aeruginosa (ATCC 27853), revealed that the dendrimeric peptides have antimicrobial activity in the low micromolar range (0.5 -- 4 µM) which was 10 times more potent than the monomer peptides. Under high salt concentrations (150 mM NaCl, 2 mM MgCl2, and 2.5 mM CaCl2) the di-branched lipopeptides retained their antimicrobial activity while the monomer peptides were not active (>100 µM). The di-branched triazole click lipopeptide, Peptide 12, was membrane lytic, showed faster killing kinetics, and exhibited antibiofilm activity against A. baumannii and MRSA and eradicated > 85 % preformed biofilms at low micromolar concentrations. The di-branched analogues were > 30-fold potent than the monomers against Candida albicans. Peptide 12 was not haemolytic (HC10 = 932.12 µM) and showed up to 40-fold higher selectivity against bacteria and fungi than the monomer peptide. Peptide 12 exhibited strong proteolytic stability (>80 % not degraded) in rat serum over 24 h whereas > 95 % of the thiol-maleimide analogue (Peptide 10) was degraded. The tetra-branched peptides showed comparable antibacterial potency to the di-branched analogues. These findings indicate that dual branching using triazole click chemistry is a promising strategy to improve the antimicrobial activity and proteolytic stability of battacin based lipopeptides. The information gathered can be used to build effective antimicrobial dendrimeric peptides as new peptide antibiotics.

Synthesis and Biological Properties of Polyphenol-Containing Linear and Dendrimeric Cationic Peptides.

Natural polyphenols are promising compounds for the pharmacological control of oxidative stress in various diseases. However, low bioavailability and rapid metabolism of polyphenols in a form of glycosides or aglycones have stimulated the search for the vehicles that would provide their efficient delivery to the systemic circulation. Conjugation of polyphenols with cationic amphiphilic peptides yields compounds with a strong antioxidant activity and ability to pass through biological barriers. Due to a broad range of biological activities characteristic of polyphenols and peptides, their conjugates can be used in the antioxidant therapy, including the treatment of viral, oncological, and neurodegenerative diseases. In this work, we synthesized linear and dendrimeric cationic amphiphilic peptides that were then conjugated with gallic acid (GA). GA is a non-toxic natural phenolic acid and an important functional element of many flavonoids with a high antioxidant activity. The obtained GA-peptide conjugates showed the antioxidant (antiradical) activity that exceeded 2-3 times the antioxidant activity of ascorbic acid. GA attachment had no effect on the toxicity and hemolytic activity of the peptides. GA-modified peptides stimulated the transmembrane transfer of the pGL3 plasmid encoding luciferase reporter gene, although GA attachment at the N-terminus of peptides reduced their transfection activity. Several synthesized conjugates demonstrated the antibacterial activity in the model of Escherichia coli Dh5α growth inhibition.

Dendrimer Platforms for Targeted Doxorubicin Delivery-Physicochemical Properties in Context of Biological Responses.

The unique structure of G4.0 PAMAM dendrimers allows a drug to be enclosed in internal spaces or immobilized on the surface. In the conducted research, the conditions for the formation of the active G4.0 PAMAM complex with doxorubicin hydrochloride (DOX) were optimized. The physicochemical properties of the system were monitored using dynamic light scattering (DLS), circular dichroism (CD), and fluorescence spectroscopy. The Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) method was chosen to determine the preferential conditions for the complex formation. The highest binding efficiency of the drug to the cationic dendrimer was observed under basic conditions when the DOX molecule was deprotonated. The decrease in the zeta potential of the complex confirms that DOX immobilizes through electrostatic interaction with the carrier's surface amine groups. The binding constants were determined from the fluorescence quenching of the DOX molecule in the presence of G4.0 PAMAM. The two-fold way of binding doxorubicin in the structure of dendrimers was visible in the Isothermal calorimetry (ITC) isotherm. Fluorescence spectra and release curves identified the reversible binding of DOX to the nanocarrier. Among the selected cancer cells, the most promising anticancer activity of the G4.0-DOX complex was observed in A375 malignant melanoma cells. Moreover, the preferred intracellular location of the complexes concerning the free drug was found, which is essential from a therapeutic point of view.

A Molecular Dynamics Simulation of Complexes of Fullerenes and Lysine-Based Peptide Dendrimers with and without Glycine Spacers.

The development of new nanocontainers for hydrophobic drugs is one of the most important tasks of drug delivery. Dendrimers with hydrophobic interiors and soluble terminal groups have already been used as drug carriers. However, the most convenient candidates for this purpose are peptide dendrimers since their interiors could be modified by hydrophobic amino acid residues with a greater affinity for the transported molecules. The goal of this work is to perform the first molecular dynamics study of the complex formation of fullerenes C60 and C70 with Lys-2Gly, Lys G2, and Lys G3 peptide dendrimers in water. We carried out such simulations for six different systems and demonstrated that both fullerenes penetrate all these dendrimers and form stable complexes with them. The density and hydrophobicity inside the complex are greater than in dendrimers without fullerene, especially for complexes with Lys-2Gly dendrimers. It makes the internal regions of complexes less accessible to water and counterions and increases electrostatic and zeta potential compared to single dendrimers. The results for complexes based on Lys G2 and Lys G3 dendrimers are similar but less pronounced. Thus, all considered peptide dendrimers and especially the Lys-2Gly dendrimer could be used as nanocontainers for the delivery of fullerenes.

Enhanced Immunomodulatory Effects of Thymosin-Alpha-1 in Combination with Polyanionic Carbosilane Dendrimers against HCMV Infection.

Resistance and toxicity associated with current treatments for human cytomegalovirus (HCMV) infection highlight the need for alternatives and immunotherapy has emerged as a promising strategy. This study examined the in vitro immunological effects of co-administration of Thymosin-alpha-1 (Tα1) and polyanionic carbosilane dendrimers (PCDs) on peripheral blood mononuclear cells (PBMCs) during HCMV infection. The biocompatibility of PCDs was assessed via MTT and LDH assays. PBMCs were pre-treated with the co-administered compounds and then exposed to HCMV for 48 h. Morphological alterations in PBMCs were observed using optical microscopy and total dendritic cells (tDCs), myeloid dendritic cells (mDCs), and plasmacytoid dendritic cells (pDCs), along with CD4+/CD8+ T cells and regulatory T cells (Treg), and were characterized using multiparametric flow cytometry. The findings revealed that Tα1 + PCDs treatments increased DC activation and maturation. Furthermore, increased co-receptor expression, intracellular IFNγ production in T cells and elevated Treg functionality and reduced senescence were evident with Tα1 + G2-S24P treatment. Conversely, reduced co-receptor expression, intracellular cytokine production in T cells, lower functionality and higher senescence in Treg were observed with Tα1 + G2S16 treatment. In summary, Tα1 + PCDs treatments demonstrate synergistic effects during early HCMV infection, suggesting their use as an alternative therapeutic for preventing virus infection.

1,3,5-Triazine as Branching Connector for the Construction of Novel Antimicrobial Peptide Dendrimers: Synthesis and Biological Characterization.

Peptides displaying antimicrobial properties are being regarded as useful tools to evade and combat antimicrobial resistance, a major public health challenge. Here we have addressed dendrimers, attractive molecules in pharmaceutical innovation and development displaying broad biological activity. Triazine-based dendrimers were fully synthesized in the solid phase, and their antimicrobial activity and some insights into their mechanisms of action were explored. Triazine is present in a large number of compounds with highly diverse biological targets with broad biological activities and could be an excellent branching unit to accommodate peptides. Our results show that the novel peptide dendrimers synthesized have remarkable antimicrobial activity against Gram-negative bacteria (E. coli and P. aeruginosa) and suggest that they may be useful in neutralizing the effect of efflux machinery on resistance.

Synthesis and Morphology Characteristics of New Highly Branched Polycaprolactone PCL.

A simple and efficient method for the synthesis of biodegradable, highly branched polycaprolactone (PCL) is presented. The solvent-free (bulk) reaction was carried out via ring opening polymerization (ROP), catalyzed by tin octanoate Sn(Oct)2, and it employed hyperbranched polyamide (HPPA) as a macro-initiator. The core-shell structure of the obtained products (PCL-HPPA), with the hyperbranched HPPA core and linear PCL chains as shell, was in the focus of the product characterization. 1H nuclear magnetic resonance (1H NMR) and elemental analysis confirmed the covalent incorporation of the HPPA in the products, as well as a high degree of grafting conversion of its amino functional groups. Confocal Raman Micro spectroscopy, and especially Time-of-Flight Secondary Ion Mass Spectrometry, further supported the existence of a core-shell structure in the products. Direct observation of macromolecules by means of cryogenic transmission electron microscopy, as well as gel permeation chromatography (GPC), suggested the existence of a minor 'aggregated' product fraction with multiple HPPA cores, which was attributed to transesterification reactions. Differential scanning calorimetry, as well as X-ray diffraction, demonstrated that the PCL-HPPA polymers displayed a similar degree of crystallinity to linear neat PCL, but that the branched products possessed smaller and less regular crystallites.

Anti-quorum sensing activity of poly-amidoamine dendrimer generation 5 dendrimer loaded kinase inhibitor peptide against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant concern in both healthcare and community settings, as it causes numerous infections worldwide with high morbidity and mortality rates. One promising strategy is to target the quorum sensing (QS) system of MRSA using a dendrimer loaded with kinase inhibitor peptide. The present investigation has formulated a poly-amidoamine dendrimer (PAMAM) G5 dendrimer that is loaded with Quorum Quencher (QQ) peptide, which functions as a histidine kinase inhibitor. The particle average size of the formulated G5-QQ3 complex was determined to be 276 nm, and polydispersity index values of 0.33. The MIC50 for the formulated nanoparticles was 18 µM as demonstrated by a growth assay. Furthermore, the G5-QQ3 complex was able to inhibit the hemolysis activity of the MRSA with a concentration of 10 µM, and for Staphylococcus aureus was 3 µM. The G5-QQ3 complex possesses the ability to inhibit, penetrate, and eradicate biofilm in MRSA, Staphylococcus aureus, and different agr mutants with inhibition percentages ranging from 60 to 72%. Furthermore, live/dead viability assay confirmed the ability of the formulated nanoparticles to effectively kill all strains within the biofilm structure as evidenced by a confocal microscope, and the cytotoxicity of the G5-QQ3 complex was dose-dependent (p < 0.05). against RAW 264.7 cells. In general, the study confirmed that encapsulating QQ3 peptide within PAMAM G5 dendrimer results in a potent anti-virulence and anti-bacterial action and suggests a synergistic effect. The findings of this study have significant implications for the development of new treatments for MRSA infections, which are a major public health concern.

Synthesis and Detection of BODIPY-, Biotin-, and 19 F- Labeled Single-Entity Dendritic Heparan Sulfate Mimetics.

Heparin and heparan sulfate (HS) are naturally occurring mammalian glycosaminoglycans, and their synthetic and semi-synthetic mimetics have attracted significant interest as potential therapeutics. However, understanding the mechanism of action by which HS, heparin, and HS mimetics have a biological effect is difficult due to their highly charged nature, broad protein interactomes, and variable structures. To address this, a library of novel single-entity dendritic mimetics conjugated to BODIPY, Fluorine-19 (19 F), and biotin was synthesized for imaging and localization studies. The novel dendritic scaffold allowed for the conjugation of labeling moieties without reducing the number of sulfated capping groups, thereby better mimicking the multivalent nature of HS-protein interactions. The 19 F labeled mimetics were assessed in phantom studies and were detected at concentrations as low as 5 mM. Flow cytometric studies using a fluorescently labeled mimetic showed that the compound associated with immune cells from tumors more readily than splenic counterparts and was directed to endosomal-lysosomal compartments within immune cells and cancer cells. Furthermore, the fluorescently labeled mimetic entered the central nervous system and was detectable in brain-infiltrating immune cells 24 hours after treatment. Here, we report the enabling methodology for rapidly preparing various labeled HS mimetics and molecular probes with diverse potential therapeutic applications.

Dendrimers as nanoscale vectors: Unlocking the bars of cancer therapy.

Chemotherapy is the first choice in the treatment of cancer and is always preferred to other approaches such as radiation and surgery, but it has never met the need of patients for a safe and effective drug. Therefore, new advances in cancer treatment are now needed to reduce the side effects and burdens associated with chemotherapy for cancer patients. Targeted treatment using nanotechnology are now being actively explored as they could effectively deliver therapeutic agents to tumor cells without affecting normal cells. Dendrimers are promising nanocarriers with distinct physiochemical properties that have received considerable attention in cancer therapy studies, which is partly due to the numerous functional groups on their surface. In this review, we discuss the progress of different types of dendrimers as delivery systems in cancer therapy, focusing on the challenges, opportunities, and functionalities of the polymeric molecules. The paper also reviews the various role of dendrimers in their entry into cells via endocytosis, as well as the molecular and inflammatory pathways in cancer. In addition, various dendrimers-based drug delivery (e.g., pH-responsive, enzyme-responsive, redox-responsive, thermo-responsive, etc.) and lipid-, amino acid-, polymer- and nanoparticle-based modifications for gene delivery, as well as co-delivery of drugs and genes in cancer therapy with dendrimers, are presented. Finally, biosafety concerns and issues hindering the transition of dendrimers from research to the clinic are discussed to shed light on their clinical applications.

Nano-biotechnology in tumour and cancerous disease: A perspective review.

In recent years, drug manufacturers and researchers have begun to consider the nanobiotechnology approach to improve the drug delivery system for tumour and cancer diseases. In this article, we review current strategies to improve tumour and cancer drug delivery, which mainly focuses on sustaining biocompatibility, biodistribution, and active targeting. The conventional therapy using cornerstone drugs such as fludarabine, cisplatin etoposide, and paclitaxel has its own challenges especially not being able to discriminate between tumour versus normal cells which eventually led to toxicity and side effects in the patients. In contrast to the conventional approach, nanoparticle-based drug delivery provides target-specific delivery and controlled release of the drug, which provides a better therapeutic window for treatment options by focusing on the eradication of diseased cells via active targeting and sparing normal cells via passive targeting. Additionally, treatment of tumours associated with the brain is hampered by the impermeability of the blood-brain barriers to the drugs, which eventually led to poor survival in the patients. Nanoparticle-based therapy offers superior delivery of drugs to the target by breaching the blood-brain barriers. Herein, we provide an overview of the properties of nanoparticles that are crucial for nanotechnology applications. We address the potential future applications of nanobiotechnology targeting specific or desired areas. In particular, the use of nanomaterials, biostructures, and drug delivery methods for the targeted treatment of tumours and cancer are explored.

Research Status of Dendrimer Micelles in Tumor Therapy for Drug Delivery.

Dendrimers are a family of polymers with highly branched structure, well-defined composition, and extensive functional groups, which have attracted great attention in biomedical applications. Micelles formed by dendrimers are ideal nanocarriers for delivering anticancer agents due to the explicit study of their characteristics of particle size, charge, and biological properties such as toxicity, blood circulation time, biodistribution, and cellular internalization. Here, the classification, preparation, and structure of dendrimer micelles are reviewed, and the specific functional groups modified on the surface of dendrimers for tumor active targeting, stimuli-responsive drug release, reduced toxicity, and prolonged blood circulation time are discussed. In addition, their applications are summarized as various platforms for biomedical applications related to cancer therapy including drug delivery, gene transfection, nano-contrast for imaging, and combined therapy. Other applications such as tissue engineering and biosensor are also involved. Finally, the possible challenges and perspectives of dendrimer micelles for their further applications are discussed.

Colloidal Polymer-Templated Formation of Inorganic Nanocrystals and their Emerging Applications.

Inorganic nanocrystals possess unique physicochemical properties compared to their bulk counterparts. Stabilizing agents are commonly used for the preparation of inorganic nanocrystals with controllable properties. Particularly, colloidal polymers have emerged as general and robust templates for in situ formation and confinement of inorganic nanocrystals. In addition to templating and stabilizing inorganic nanocrystals, colloidal polymers can tailor their physicochemical properties such as size, shape, structure, composition, surface chemistry, and so on. By incorporating functional groups into colloidal polymers, desired functions can be integrated with inorganic nanocrystals, advancing their potential applications. Here, recent advances in the colloidal polymer-templated formation of inorganic nanocrystals are reviewed. Seven types of colloidal polymers, including dendrimer, polymer micelle, stare-like block polymer, bottlebrush polymer, spherical polyelectrolyte brush, microgel, and single-chain nanoparticle, have been extensively applied for the synthesis of inorganic nanocrystals. Different strategies for the development of these colloidal polymer-templated inorganic nanocrystals are summarized. Then, their emerging applications in the fields of catalysis, biomedicine, solar cells, sensing, light-emitting diodes, and lithium-ion batteries are highlighted. Last, the remaining issues and future directions are discussed. This review will stimulate the development and application of colloidal polymer-templated inorganic nanocrystals.

An Intelligent Vascular Disrupting Dendritic Nanodevice Incorporating Copper Sulfide Nanoparticles for Immune Modulation-Mediated Combination Tumor Therapy.

Development of intelligent nanoplatforms that can simultaneously target multiple factors associated with tumor growth and metastasis remains an extreme challenge. Here, an intelligent dendritic nanodevice incorporating both copper sulfide nanoparticles (CuS NPs) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA, a vascular disrupting agent) within the dendrimer internal cavities and surface modified with a targeting agent LyP-1 peptide is reported. The resulting generation 5 (G5) dendrimer-based nanodevice, known as G5-PEG-LyP-1-CuS-DMXAA NPs (GLCD NPs), possess good colloidal stability, pH-sensitive drug release kinetics, and high photothermal conversion efficiency (59.3%). These functional GLCD NPs exert a LyP-1-targeted killing effect on breast tumors by combining CuS-mediated photothermal therapy (PTT) and DMXAA-induced vascular disruption, while also triggering antitumor immune responses through PTT-induced immunogenic cell death and DMXAA-mediated immune regulation via M1 polarization of tumor-associated macrophages and dendritic cell maturation. In addition, with the LyP-1-mediated proapoptotic activity, the GLCD NPs can specifically kill tumor lymphatic endothelial cells. The simultaneous disruption of tumor blood vessels and lymphatic vessels cuts off the two main pathways of tumor metastasis, which plays a two-pronged role in inhibiting lung metastasis of the breast cancer model. Thus, the developed GLCD NPs represent an advanced intelligent nanoformulation for immune modulation-mediated combination tumor therapy with potential for clinical translations.

Dendrimer Based Binders Enable Stable Operation of Silicon Microparticle Anodes in Lithium-Ion Batteries.

High-capacity anode materials (e.g., Si) are highly needed for high energy density battery systems, but they usually suffer from low initial coulombic efficiency (CE), short cycle life, and low-rate capability caused by large volume changes during the charge and discharge process. Here, a novel dendrimer-based binder for boosting the electrochemical performance of Si anodes is developed. The polyamidoamine (PMM) dendrimer not only can be used as binder, but also can be utilized as a crosslinker to construct 3D polyacrylic acid (PAA)-PMM composite binder for high-performance Si microparticles anodes. Benefiting from maximum interface interaction, strong average peeling force, and high elastic recovery rate of PAA-PMM composite, the Si electrode based on PAA-PMM achieves a high specific capacity of 3590 mAh g-1 with an initial CE of 91.12%, long-term cycle stability with 69.80% retention over 200 cycles, and outstanding rate capability (1534.8 mAh g-1 at 3000 mA g-1 ). This work opens a new avenue to use dendrimer chemistry for the development of high-performance binders for high-capacity anode materials.

ACTIVE-BAPO - A Versatile Transfer Agent for Photoactive Bis(acyl)phosphane Oxide Units.

A N-hydroxy succinimide (NHS) ester substituted bis(acyl)phosphane oxide (ACTIVE-BAPO) was prepared by phospha-Michael addition and used for an easy one-step BAPO ligation with substrates containing primary amino groups, such as amino acids, proteins, and poly(amidoamine) (PAMAM) dendrimers. Thereby, a range of new molecular and polymeric photoinitators was obtained. Real-time photo-rheology experiments demonstrated the outstanding efficiency of the PAMAM BAPOs as photoinitiators for free radical polymerization. Remarkably, it is found that PAMAM BAPOs also act as crosslinking agents to convert monofunctional methacrylate monomers into thermosetting networks without any further additives. Depending on the number of the attached BAPOs, thermosets with a different degree of crosslinking and swelling capability in water were obtained.