Injectable PAMAM dendrimer-PEG hydrogels for the treatment of genital infections: formulation and in vitro and in vivo evaluation.

Local intravaginal drug therapy is preferred for treatment of ascending genital infections during pregnancy. In the present study, an in situ forming biodegradable hydrogel for sustained release of amoxicillin in the cervicovaginal region is described. A generation 4 poly(amidoamine) [G4-(NH(2))(64)] dendrimer with peripheral thiopyridyl terminations is cross-linked with 8-arm polyethylene glycol (PEG) bearing thiol terminations.

Transfer of PAMAM dendrimers across human placenta: prospects of its use as drug carrier during pregnancy.

Dendrimers offer significant potential as nanocarriers for targeted delivery of drugs and imaging agents. The objectives of this study were to evaluate the transplacental transport, kinetics and biodistribution of PAMAM dendrimers ex-vivo across the human placenta in comparison with antipyrine, a freely diffusible molecule, using dually perfused re-circulating term human placental lobules. The purpose of this study is to determine if dendrimers as drug carriers can be used to design drug delivery systems directed at selectively treating either the mother or the fetus.

Doxycycline hydrogels with reversible disulfide crosslinks for dermal wound healing of mustard injuries.

Doxycycline hydrogels containing reversible disulfide crosslinks were investigated for a dermal wound healing application. Nitrogen mustard (NM) was used as a surrogate to mimic the vesicant effects of the chemical warfare agent sulfur mustard. An 8-arm-poly(ethylene glycol) (PEG) polymer containing multiple thiol (-SH) groups was crosslinked using hydrogen peroxide (H(2)O(2) hydrogel) or 8-arm-S-thiopyridyl (S-TP hydrogel) to form a hydrogel in situ.

Inhibition of bacterial growth and intramniotic infection in a guinea pig model of chorioamnionitis using PAMAM dendrimers.

Dendrimers have emerged as topical microbicides to treat vaginal infections. This study explores the in vitro, in vivo antimicrobial activity of PAMAM dendrimers, and the associated mechanism. Interestingly, topical cervical application of 500 microg of generation-4 neutral dendrimer (G(4)-PAMAM-OH) showed potential to treat the Escherichia coli induced ascending uterine infection in guinea pig model of chorioamnionitis.

Amino acid-functionalized dendrimers with heterobifunctional chemoselective peripheral groups for drug delivery applications.

Dendrimers have emerged as multifunctional carriers for targeted drug delivery, gene delivery and imaging. Improving the functional versatility at the surface for carrying multiple conjugation reactions is becoming vital. Typically, generation four polyamidoamine (G4-PAMAM) dendrimers bear approximately 64 symmetrical end groups, often requiring different spacers to conjugate various functional groups (drugs and targeting moities), increasing the synthetic steps.

Transport and biodistribution of dendrimers across human fetal membranes: implications for intravaginal administration of dendrimer-drug conjugates.

Dendrimers are emerging as promising topical antimicrobial agents, and as targeted nanoscale drug delivery vehicles. Topical intravaginal antimicrobial agents are prescribed to treat the ascending genital infections in pregnant women. The fetal membranes separate the extra-amniotic space and fetus.

Dendrimer-based drug and imaging conjugates: design considerations for nanomedical applications.

Dendrimers are members of a versatile, fourth new class of polymer architecture (i.e. dendritic polymers after traditional linear, crosslinked and branched types).

Doxycycline loaded poly(ethylene glycol) hydrogels for healing vesicant-induced ocular wounds.

Half mustard (CEES) and nitrogen mustard (NM) are commonly used surrogates and vesicant analogs of the chemical warfare agent sulfur mustard. In the current study, in situ forming poly(ethylene glycol) (PEG)-based doxycycline hydrogels are developed and evaluated for their wound healing efficacy in CEES and NM-exposed rabbit corneas in organ culture. The hydrogels, characterized by UV-Vis spectrophotometry, rheometry, and swelling kinetics, showed that the hydrogels are optically transparent, have good mechanical strength and a relatively low degree of swelling (<7%).

Designing a self-associated cationic polymer for enhanced compatibility, palatability, and gastric release of cefuroxime axetil.

Cefuroxime axetil (CA) has exhibited interactions with the polymers hydroxypropyl methylcellulose phthalate, cellulose acetate trimellitate, and Eudragit E resulting in the generation of unacceptable amounts of impurities and degradation. Formulations, which mask the bitter taste of CA and release it immediately in the stomach, have therefore not been possible. In an attempt to overcome the interaction with CA, we report a self-associated cationic polymer (NREP) containing methyl methacrylate (MMA), 2-hydroxy ethylmethacrylate (HEMA), and 4-vinyl pyridine (4-VP).

Blends of reverse enteric polymer with Enteric and pH-independent polymers: mechanistic investigations for tailoring drug release.

Blends of conventional reverse enteric polymer with enteric polymers result in insoluble polyelectrolyte complexes and hence cannot be used in film coatings. We report a new set of miscible blends of a new reverse enteric polymer (NREP) synthesized by us with enteric and pH-independent polymers. The nature of interactions between polymers in the blends has been established by analyzing Fourier transform infrared (FTIR) spectra.