This review summarizes the current literature regarding stereocomplexation of different polyesters based on α‐ as well as β‐hydroxy acids beyond the well‐known poly(lactic acid). Representing the initial step toward stereocomplexation, synthetic approaches needed to obtain and analyze isotactic polyesters are summarized. The basic technologies for the preparation and characterization of the respective stereocomplexes (SCs) are described, and published material properties are related to the structure of the respective polyesters. The variety of available SC materials is very limited despite the multiple options provided by state‐of‐the‐art stereoselective monomer synthesis and polymerization methods. A combination of knowledge from the three scientific areas (i.e., organic chemistry, synthetic macromolecular chemistry, and materials science) thus has enormous potential to create novel materials with additional features enabled by the introduction of functional moieties to such materials besides the adjustment of thermal as well as mechanical properties.

Self-assembly of polyesters like PLLA and PDLA into stereocomplexes (SCs) is an interesting approach to tailor physical properties of polymeric nanoparticles without affecting their hydrophilicity. Here, we use the stereocomplexation of P(LLA-stat-EtGly) and P(DLA-stat-EtGly) (EtGly: 3-ethylglycolide) to tune the melting temperature (T m ) and degree of crystallinity (w c ) of the bulk polymer. Using time-dependent blending experiments and characterization techniques, such as dynamic light scattering, wide-angle X-ray spectroscopy, differential scanning calorimetry, and atomic force microscopy, we tested the hypothesis that the amount of SCs within the nanoparticles impacts their mechanical properties. Our results show that T m and w c can be adjusted via the EtGly content. Interestingly, mechanical properties of the nanoparticles depend on the EtGly content as well as the self-assembly time of SCs before nanoparticle formation. This offers a high potential for their application in drug delivery, where their tunable properties will allow to adjust degradation and drug release behavior.

The novel lactide isomer 3-ethyl-1,4-dioxane-2,5-dione (3-ethylglycolide, EtGly) represented the basis for the development of polyesters varying crystallinity.

A benzoin-derived diol linker was synthesized and used to generate biocompatible polyesters that can be fully decomposed on demand upon UV irradiation. Extensive structural optimization of the linker unit was performed to enable the defined encapsulation of diverse organic compounds in the polymeric structures and allow for a well-controllable polymer cleavage process. Selective tracking of the release kinetics of encapsulated model compounds from the polymeric nano- and microparticle containers was performed by confocal laser scanning microscopy in a proof-of-principle study. The physicochemical properties of the incorporated and released model compounds ranged from fully hydrophilic to fully hydrophobic. The demonstrated biocompatibility of the utilized polyesters and degradation products enables their use in advanced applications, for example, for the smart packaging of UV-sensitive pharmaceuticals, nutritional components, or even in the area of spatially selective self-healing processes.

We describe the synthesis of hydrophilic poly(poly-(ethylene glycol) methyl ether methacrylate) (PmPEGMA) and hydrophobic poly(methyl methacrylate) (PMMA) caspofungin conjugates by a post-polymerization modification of copolymers containing 10 mol % pentafluorophenyl methacrylate (PFPMA), which were obtained via reversible addition−fragmentation chain transfer copolymerization. The coupling of the clinically used antifungal caspofungin was confirmed and quantified in detail by a combination of 1 H-, 19 Fand diffusion-ordered NMR spectroscopy, UV−vis spectroscopy, and size exclusion chromatography. The trifunctional amine-containing antifungal was attached via several amide bonds to the hydrophobic PMMA, but sterical hindrance induced by the mPEGMA side chains prohibited intramolecular double functionalization. Both polymer−drug conjugates revealed activity against important human-pathogenic fungi, that is, two strains of Aspergillus fumigatus and one strain of Candida albicans (2.5 mg L −1 < MEC < 8 mg L −1 , MIC 50 = 4 mg L −1 ), whereas RAW 264.7 macrophages as well as HeLa cells remained unaffected at these concentrations.