An insight on sources and biodegradation of bioplastics: a review

Durability and affordability are two main reasons for the widespread consumption of plastic in the world. However, the inability of these materials to undergo degradation has become a significant threat to the environment and human health To address this issue, bioplastics have emerged as a promising alternative. Bioplastics are obtained from renewable and sustainable biomass and have a lower carbon footprint and emit fewer greenhouse gases than petroleum-based plastics. The use of these bioplastics sourced from renewable biomass can also reduce the dependency on fossil fuels, which are limited in availability. This review provides an elaborate comparison of biodegradation rates of potential bioplastics in soil from various sources such as biomass, microorganisms, and monomers. These bioplastics show great potential as a replacement for conventional plastics due to their biodegradable and diverse properties.

Recent Advances of Poly(ester amide)s-Based Biomaterials

Biodegradable and biocompatible biomaterials have offered much more opportunities from an engineering standpoint for treating diseases and maintaining health. Poly(ester amide)s (PEAs), as an outstanding family among such biomaterials, have risen overwhelmingly in the past decades. These synthetic polymers have easily and widely available raw materials and a diversity of synthetic approaches, which have attracted considerable attention. More importantly, combining the superiorities of polyamides and polyesters, PEAs have emerged with better functions. They could have improved biodegradability, biocompatibility, and cell-material interactions. The PEAs derived from α-amino acids even allow the introduction of pendant sites for further modification or functionalization. Meanwhile, it is gradually recognized that the chemical structures are closely related to the physiochemical and biological properties of PEAs so that their properties can be precisely controlled. PEAs therefore become significant materials in the biomedical fields. This review will attempt to summarize the recent progress in the development of PEAs with respect to the preparation materials and methods, structure-property relationships along with their latest biomedical accomplishments, especially for drug delivery and tissue engineering.

Preparation, characterization and degradation study of novel sulfonated furanic poly(ester-amide)s

A series of novel-sulfonated furanic polyesteramides have been synthesized by polycondensation in the melt-phase. The copolymers were obtained with reasonable molecular weights and high inherent viscosities between 0.2 and 0.4 dL/g. The hydrolytic degradability of polyesteramides was enhanced by the increasing of amide units in the copolymers backbone.

Renewable Isohexide-Based, Hydrolytically Degradable Poly(silyl ether)s with High Thermal Stability

Several degradable poly(silyl ether)s (PSEs) have been synthesized by dehydrogenative cross-coupling between bio-based 1,4:3,6-dianhydrohexitols (isosorbide and isomannide) and commercially available hydrosilanes. An air-stable manganese salen nitrido complex [Mn^V N(salen-3,5-tBu₂ )] was employed as the catalyst. High-molecular-weight polymer was obtained from isosorbide and diphenylsilane (M_n up to 17000 g mol^-1 ). Thermal analysis showed that these PSEs possessed high thermal stability with thermal decomposition temperatures (T_-5 % ) of 347-446 °C and glass transition temperatures of 42-120 °C. Structure-property analysis suggested that steric bulk and molecular weight have a significant influence to determine the thermal properties of synthesized polymers. Importantly, these polymers were degraded effectively to small molecules under acidic and basic hydrolysis conditions.

Design and synthesis of new s-triazine polymers and their application as nanoparticulate drug delivery systems

The feasibility ofs-triazine polyamides to fabricate celecoxib-loaded nanoparticles.

Poly(ester amide)s: recent insights into synthesis, stability and biomedical applications

Recent progress in polyesteramides, which are important polymers that can combine the properties of polyesters and polyamides, is described with a focus on synthesis and their application as biomaterials.

Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s

Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

Synthesis and characterization of functional elastomeric poly(ester amide) co-polymers

A new family of random co-poly(ester amides)s (co-PEAs) having reactive pendant functional carboxylic acid groups were synthesized by co-polycondensation of di-p-toluenesulfonic acid salts of bis-(L-alpha-amino acid (L-leucine and/or L-phenylalanine)) alpha,omega-alkylene diesters with active diesters of dicarboxylic acids using di-p-toluenesulfonic acid salt of L-lysine benzyl ester as a co-monomer. The lateral benzyl ester groups in the L-lysine segment of co-PEAs were subsequently transformed into free COOH groups by catalytic hydrogenolysis using Pd black as a catalyst. The co-PEA-based polyacids obtained, as well as the original co-PEA having lateral benzyl ester groups were characterized by standard methods. In vitro biodegradation studies in the presence of hydrolases like alpha-chymotrypsin and lipase showed significant enzymatic-catalyzed biodegradation of these co-PEAs. These co-PEA-based polyacids were used for covalent attachment of iminoxyl radicals (4-amino-TEMPO) and in vitro biodegradation of 4-aminoTEMPO attached polymer was studied along with releasing kinetic of iminoxyl radical.

Biodegradable functional poly(ester amide)s with pendant hydroxyl functional groups: synthesis, characterization, fabrication and in vitro cellular response

The synthesis of a new family of biodegradable α-amino acid poly(ester amide)s (AA-PEAs) with pendant benzyl ether groups and hydroxyl functional groups is reported. The synthetic strategy employs the ring opening reaction of O-benzyl-L-serine-N-carboxyanhydride with di-p-toluenesulfonic acid salts of bis-L-valine butane-1,4-diester, followed by solution polycondesation reactions with di-p-nitrophenyl sebacate in N,N-dimethylacetamide. Catalytic hydrogenation of the resulting benzyl ether protected AA-PEAs (PEA-Ser-Bzs) was performed to restore the hydroxyl functional groups in the functionalized AA-PEAs (PEA-Ser-OH). All resulting polymers were characterized by standard physico-chemical methods. The pendant hydroxyl groups in PEA-Ser-OH were used to fabricate AA-PEA-based gels via acrylation and photo-gelation. The cell-polymer interactions of PEA-Ser-Bz and PEA-Ser-OH were evaluated in terms of cell attachment and proliferation assay using bovine aortic endothelial cells (BAECs) as well as fibroblasts. The cell culture data indicated that the hydrophobic/hydrophilic characteristics (from contact angle data) of these AA-PEAs could significantly affect the interaction between BAECs and AA-PEA. This finding may provide additional possible applications for this new family of functionalized AA-PEA polymers.

Synthesis of bis-spermine dimers that are potent polyamine transport inhibitors

A series of novel spermine dimer analogues was synthesized and assessed for their ability to inhibit spermidine transport into MDA-MB-231 breast carcinoma cells. Two spermine molecules were tethered via their N(1) primary amines with naphthalenedisulfonic acid, adamantanedicarboxylic acid and a series of aliphatic dicarboxylic acids. The linked spermine analogues were potent polyamine transport inhibitors and inhibited cell growth cytostatically in combination with a polyamine synthesis inhibitor. Variation in the linker length did not alter polyamine transport inhibition. The amount of charge on the molecule may influence the molecular interaction with the transporter since the most potent spermidine transport inhibitors contained 5-6 positive charges.